diff --git a/src/internal.c b/src/internal.c
index 38cd26e9d8..1bf5963aee 100644
--- a/src/internal.c
+++ b/src/internal.c
@@ -266,6 +266,49 @@ static int SSL_hmac(WOLFSSL* ssl, byte* digest, const byte* in, word32 sz,
 #endif /* !WOLFSSL_NO_TLS12 */
 
 
+#if !defined(NO_CERT) && defined(WOLFSSL_BLIND_PRIVATE_KEY)
+int wolfssl_priv_der_blind(WC_RNG* rng, DerBuffer* key, DerBuffer** mask)
+{
+    int ret = 0;
+    WC_RNG local_rng;
+
+    if (key != NULL) {
+        if (*mask != NULL) {
+            FreeDer(mask);
+        }
+        ret = AllocDer(mask, key->length, key->type, key->heap);
+        if ((ret == 0) && (rng == NULL)) {
+            if (wc_InitRng(&local_rng) != 0) {
+                ret = RNG_FAILURE_E;
+            }
+            else {
+                rng = &local_rng;
+            }
+        }
+        if (ret == 0) {
+             ret = wc_RNG_GenerateBlock(rng, (*mask)->buffer, (*mask)->length);
+        }
+        if (ret == 0) {
+            xorbuf(key->buffer, (*mask)->buffer, (*mask)->length);
+        }
+
+        if (rng == &local_rng) {
+            wc_FreeRng(rng);
+        }
+    }
+
+    return ret;
+}
+
+void wolfssl_priv_der_unblind(DerBuffer* key, DerBuffer* mask)
+{
+    if (key != NULL) {
+        xorbuf(key->buffer, mask->buffer, mask->length);
+    }
+}
+#endif
+
+
 #if defined(WOLFSSL_RENESAS_FSPSM_TLS) || defined(WOLFSSL_RENESAS_TSIP_TLS)
 #include <wolfssl/wolfcrypt/port/Renesas/renesas_cmn.h>
 #endif
@@ -2604,11 +2647,17 @@ void SSL_CtxResourceFree(WOLFSSL_CTX* ctx)
         ForceZero(ctx->privateKey->buffer, ctx->privateKey->length);
     }
     FreeDer(&ctx->privateKey);
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    FreeDer(&ctx->privateKeyMask);
+#endif
 #ifdef WOLFSSL_DUAL_ALG_CERTS
     if (ctx->altPrivateKey != NULL && ctx->altPrivateKey->buffer != NULL) {
         ForceZero(ctx->altPrivateKey->buffer, ctx->altPrivateKey->length);
     }
     FreeDer(&ctx->altPrivateKey);
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    FreeDer(&ctx->altPrivateKeyMask);
+#endif
 #endif /* WOLFSSL_DUAL_ALG_CERTS */
 #ifdef OPENSSL_ALL
     wolfSSL_EVP_PKEY_free(ctx->privateKeyPKey);
@@ -6763,14 +6812,45 @@ int SetSSL_CTX(WOLFSSL* ssl, WOLFSSL_CTX* ctx, int writeDup)
 #ifdef WOLFSSL_TLS13
     ssl->buffers.certChainCnt = ctx->certChainCnt;
 #endif
+#ifndef WOLFSSL_BLIND_PRIVATE_KEY
     ssl->buffers.key      = ctx->privateKey;
+#else
+    if (ctx->privateKey != NULL) {
+        AllocCopyDer(&ssl->buffers.key, ctx->privateKey->buffer,
+            ctx->privateKey->length, ctx->privateKey->type,
+            ctx->privateKey->heap);
+        ssl->buffers.weOwnKey = 1;
+        /* Blind the private key for the SSL with new random mask. */
+        wolfssl_priv_der_unblind(ssl->buffers.key, ctx->privateKeyMask);
+        ret = wolfssl_priv_der_blind(ssl->rng, ssl->buffers.key,
+            &ssl->buffers.keyMask);
+        if (ret != 0) {
+            return ret;
+        }
+    }
+#endif
     ssl->buffers.keyType  = ctx->privateKeyType;
     ssl->buffers.keyId    = ctx->privateKeyId;
     ssl->buffers.keyLabel = ctx->privateKeyLabel;
     ssl->buffers.keySz    = ctx->privateKeySz;
     ssl->buffers.keyDevId = ctx->privateKeyDevId;
 #ifdef WOLFSSL_DUAL_ALG_CERTS
-    ssl->buffers.altKey      = ctx->altPrivateKey;
+#ifndef WOLFSSL_BLIND_PRIVATE_KEY
+    ssl->buffers.altKey   = ctx->altPrivateKey;
+#else
+    if (ctx->altPrivateKey != NULL) {
+        AllocCopyDer(&ssl->buffers.altkey, ctx->altPrivateKey->buffer,
+            ctx->altPrivateKey->length, ctx->altPrivateKey->type,
+            ctx->altPrivateKey->heap);
+        /* Blind the private key for the SSL with new random mask. */
+        wolfssl_priv_der_unblind(ssl->buffers.altKey, ctx->altPrivateKeyMask);
+        ret = wolfssl_priv_der_blind(ssl->rng, ssl->buffers.altKey,
+            &ssl->buffers.altKeyMask);
+        if (ret != 0) {
+            return ret;
+        }
+    }
+#endif
     ssl->buffers.altKeyType  = ctx->altPrivateKeyType;
     ssl->buffers.altKeyId    = ctx->altPrivateKeyId;
     ssl->buffers.altKeyLabel = ctx->altPrivateKeyLabel;
@@ -8518,8 +8598,14 @@ void FreeHandshakeResources(WOLFSSL* ssl)
     }
 #endif /* !NO_DH */
 
-#ifndef NO_CERTS
-    wolfSSL_UnloadCertsKeys(ssl);
+#if !defined(NO_CERTS) && !defined(OPENSSL_EXTRA) && \
+    !defined(WOLFSSL_WPAS_SMALL)
+#ifndef WOLFSSL_POST_HANDSHAKE_AUTH
+    if (ssl->options.side != WOLFSSL_CLIENT_END)
+#endif
+    {
+        wolfSSL_UnloadCertsKeys(ssl);
+    }
 #endif
 #ifdef HAVE_PK_CALLBACKS
 #if defined(WOLFSSL_TLS13) && defined(WOLFSSL_POST_HANDSHAKE_AUTH)
@@ -28322,6 +28408,10 @@ int DecodeAltPrivateKey(WOLFSSL *ssl, word32* length)
         ERROR_OUT(NO_PRIVATE_KEY, exit_dapk);
     }
 
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    wolfssl_priv_der_unblind(ssl->buffers.altKey, ssl->buffers.altKeyMask);
+#endif
+
 #ifdef WOLF_PRIVATE_KEY_ID
     if (ssl->buffers.altKeyDevId != INVALID_DEVID &&
         (ssl->buffers.altKeyId || ssl->buffers.altKeyLabel)) {
@@ -28724,6 +28814,16 @@ int DecodeAltPrivateKey(WOLFSSL *ssl, word32* length)
     (void)length;
 
 exit_dapk:
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    if (ret == 0) {
+        ret = wolfssl_priv_der_blind(ssl->rng, ssl->buffers.altKey,
+            &ssl->buffers.altKeyMask);
+    }
+    else {
+        wolfssl_priv_der_unblind(ssl->buffers.key, ssl->buffers.keyMask);
+    }
+#endif
+
     if (ret != 0) {
         WOLFSSL_ERROR_VERBOSE(ret);
     }
@@ -32746,6 +32846,10 @@ int SendCertificateVerify(WOLFSSL* ssl)
     WOLFSSL_START(WC_FUNC_CERTIFICATE_VERIFY_SEND);
     WOLFSSL_ENTER("SendCertificateVerify");
 
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    wolfssl_priv_der_unblind(ssl->buffers.key, ssl->buffers.keyMask);
+#endif
+
 #ifdef WOLFSSL_ASYNC_IO
     if (ssl->async == NULL) {
         ssl->async = (struct WOLFSSL_ASYNC*)
@@ -32792,6 +32896,10 @@ int SendCertificateVerify(WOLFSSL* ssl)
         case TLS_ASYNC_BEGIN:
         {
             if (ssl->options.sendVerify == SEND_BLANK_CERT) {
+            #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+                wolfssl_priv_der_unblind(ssl->buffers.key,
+                    ssl->buffers.keyMask);
+            #endif
                 return 0;  /* sent blank cert, can't verify */
             }
 
@@ -33196,6 +33304,15 @@ int SendCertificateVerify(WOLFSSL* ssl)
     } /* switch(ssl->options.asyncState) */
 
 exit_scv:
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    if (ret == 0) {
+        ret = wolfssl_priv_der_blind(ssl->rng, ssl->buffers.key,
+            &ssl->buffers.keyMask);
+    }
+    else {
+        wolfssl_priv_der_unblind(ssl->buffers.key, ssl->buffers.keyMask);
+    }
+#endif
 
     WOLFSSL_LEAVE("SendCertificateVerify", ret);
     WOLFSSL_END(WC_FUNC_CERTIFICATE_VERIFY_SEND);
@@ -33859,6 +33976,10 @@ static int DoSessionTicket(WOLFSSL* ssl, const byte* input, word32* inOutIdx,
         WOLFSSL_START(WC_FUNC_SERVER_KEY_EXCHANGE_SEND);
         WOLFSSL_ENTER("SendServerKeyExchange");
 
+    #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+        wolfssl_priv_der_unblind(ssl->buffers.key, ssl->buffers.keyMask);
+    #endif
+
     #ifdef WOLFSSL_ASYNC_IO
         if (ssl->async == NULL) {
             ssl->async = (struct WOLFSSL_ASYNC*)
@@ -35415,6 +35536,16 @@ static int DoSessionTicket(WOLFSSL* ssl, const byte* input, word32* inOutIdx,
 
     exit_sske:
 
+    #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+        if (ret == 0) {
+            ret = wolfssl_priv_der_blind(ssl->rng, ssl->buffers.key,
+                &ssl->buffers.keyMask);
+        }
+        else {
+            wolfssl_priv_der_unblind(ssl->buffers.key, ssl->buffers.keyMask);
+        }
+    #endif
+
         WOLFSSL_LEAVE("SendServerKeyExchange", ret);
         WOLFSSL_END(WC_FUNC_SERVER_KEY_EXCHANGE_SEND);
 
@@ -38937,6 +39068,10 @@ static int DefTicketEncCb(WOLFSSL* ssl, byte key_name[WOLFSSL_TICKET_NAME_SZ],
         WOLFSSL_START(WC_FUNC_CLIENT_KEY_EXCHANGE_DO);
         WOLFSSL_ENTER("DoClientKeyExchange");
 
+    #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+        wolfssl_priv_der_unblind(ssl->buffers.key, ssl->buffers.keyMask);
+    #endif
+
     #ifdef WOLFSSL_ASYNC_CRYPT
         if (ssl->async == NULL) {
             ssl->async = (struct WOLFSSL_ASYNC*)
@@ -40131,6 +40266,16 @@ static int DefTicketEncCb(WOLFSSL* ssl, byte key_name[WOLFSSL_TICKET_NAME_SZ],
 
     exit_dcke:
 
+    #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+        if (ret == 0) {
+            ret = wolfssl_priv_der_blind(ssl->rng, ssl->buffers.key,
+                &ssl->buffers.keyMask);
+        }
+        else {
+            wolfssl_priv_der_unblind(ssl->buffers.key, ssl->buffers.keyMask);
+        }
+    #endif
+
         WOLFSSL_LEAVE("DoClientKeyExchange", ret);
         WOLFSSL_END(WC_FUNC_CLIENT_KEY_EXCHANGE_DO);
     #ifdef WOLFSSL_ASYNC_CRYPT
diff --git a/src/pk.c b/src/pk.c
index 67f85fd453..02a4c4ae7b 100644
--- a/src/pk.c
+++ b/src/pk.c
@@ -11704,7 +11704,8 @@ static int wolfssl_ec_key_int_copy(ecc_key* dst, const ecc_key* src)
 
     if (ret == 0) {
         /* Copy private key. */
-        ret = mp_copy(wc_ecc_key_get_priv(src), wc_ecc_key_get_priv(dst));
+        ret = mp_copy(wc_ecc_key_get_priv((ecc_key*)src),
+            wc_ecc_key_get_priv(dst));
         if (ret != MP_OKAY) {
             WOLFSSL_MSG("mp_copy error");
         }
diff --git a/src/ssl.c b/src/ssl.c
index 6412350665..4d71886658 100644
--- a/src/ssl.c
+++ b/src/ssl.c
@@ -6339,20 +6339,54 @@ static int check_cert_key(DerBuffer* cert, DerBuffer* key, DerBuffer* altKey,
  *         WOLFSSL_FAILURE if mismatched. */
 int wolfSSL_CTX_check_private_key(const WOLFSSL_CTX* ctx)
 {
+    int res;
+
     if (ctx == NULL) {
         return WOLFSSL_FAILURE;
     }
 
 #ifdef WOLFSSL_DUAL_ALG_CERTS
-    return check_cert_key(ctx->certificate, ctx->privateKey, ctx->altPrivateKey,
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    wolfssl_priv_der_unblind(ctx->privateKey, ctx->privateKeyMask);
+    wolfssl_priv_der_unblind(ctx->altPrivateKey, ctx->altPrivateKeyMask);
+#endif
+    res = check_cert_key(ctx->certificate, ctx->privateKey, ctx->altPrivateKey,
             ctx->heap, ctx->privateKeyDevId, ctx->privateKeyLabel,
             ctx->privateKeyId, ctx->altPrivateKeyDevId, ctx->altPrivateKeyLabel,
-            ctx->altPrivateKeyId);
+            ctx->altPrivateKeyId) != 0
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    {
+        int ret;
+        ret = wolfssl_priv_der_blind(NULL, ctx->privateKey,
+            (DerBuffer**)&ctx->privateKeyMask);
+        if (ret == 0) {
+            ret = wolfssl_priv_der_blind(NULL, ctx->altPrivateKey,
+                (DerBuffer**)&ctx->altPrivateKeyMask);
+        }
+        if (ret != 0) {
+            res = WOLFSSL_FAILURE;
+        }
+    }
+#endif
 #else
-    return check_cert_key(ctx->certificate, ctx->privateKey, NULL, ctx->heap,
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    wolfssl_priv_der_unblind(ctx->privateKey, ctx->privateKeyMask);
+#endif
+    res = check_cert_key(ctx->certificate, ctx->privateKey, NULL, ctx->heap,
             ctx->privateKeyDevId, ctx->privateKeyLabel, ctx->privateKeyId,
             INVALID_DEVID, 0, 0);
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    {
+        int ret = wolfssl_priv_der_blind(NULL, ctx->privateKey,
+            (DerBuffer**)&ctx->privateKeyMask);
+        if (ret != 0) {
+            res = WOLFSSL_FAILURE;
+        }
+    }
 #endif
+#endif
+
+    return res;
 }
 #endif /* !NO_CHECK_PRIVATE_KEY */
 
@@ -6363,6 +6397,7 @@ int wolfSSL_CTX_check_private_key(const WOLFSSL_CTX* ctx)
  */
 WOLFSSL_EVP_PKEY* wolfSSL_CTX_get0_privatekey(const WOLFSSL_CTX* ctx)
 {
+    WOLFSSL_EVP_PKEY* res;
     const unsigned char *key;
     int type;
 
@@ -6399,12 +6434,22 @@ WOLFSSL_EVP_PKEY* wolfSSL_CTX_get0_privatekey(const WOLFSSL_CTX* ctx)
 
     key = ctx->privateKey->buffer;
 
-    if (ctx->privateKeyPKey != NULL)
-        return ctx->privateKeyPKey;
-    else
-        return wolfSSL_d2i_PrivateKey(type,
+    if (ctx->privateKeyPKey != NULL) {
+        res = ctx->privateKeyPKey;
+    }
+    else {
+    #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+        wolfssl_priv_der_unblind(ctx->privateKey, ctx->privateKeyMask);
+    #endif
+        res = wolfSSL_d2i_PrivateKey(type,
                 (WOLFSSL_EVP_PKEY**)&ctx->privateKeyPKey, &key,
                 (long)ctx->privateKey->length);
+    #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+        wolfssl_priv_der_unblind(ctx->privateKey, ctx->privateKeyMask);
+    #endif
+    }
+
+    return res;
 }
 #endif
 
@@ -7584,19 +7629,53 @@ WOLFSSL_EVP_PKEY* wolfSSL_d2i_PrivateKey_id(int type, WOLFSSL_EVP_PKEY** out,
  *         WOLFSSL_FAILURE if mismatched. */
 int wolfSSL_check_private_key(const WOLFSSL* ssl)
 {
+    int res = WOLFSSL_SUCCESS;
+
     if (ssl == NULL) {
         return WOLFSSL_FAILURE;
     }
 #ifdef WOLFSSL_DUAL_ALG_CERTS
-    return check_cert_key(ssl->buffers.certificate, ssl->buffers.key,
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    wolfssl_priv_der_unblind(ssl->buffers.key, ssl->buffers.keyMask);
+    wolfssl_priv_der_unblind(ssl->buffers.altKey, ssl->buffers.altKeyMask);
+#endif
+    res = check_cert_key(ssl->buffers.certificate, ssl->buffers.key,
         ssl->buffers.altKey, ssl->heap, ssl->buffers.keyDevId,
         ssl->buffers.keyLabel, ssl->buffers.keyId, ssl->buffers.altKeyDevId,
         ssl->buffers.altKeyLabel, ssl->buffers.altKeyId);
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    if (res == WOLFSSL_SUCCESS) {
+        int ret;
+        ret = wolfssl_priv_der_blind(ssl->rng, ssl->buffers.key,
+            (DerBuffer**)&ssl->buffers.keyMask);
+        if (ret == 0) {
+            ret = wolfssl_priv_der_blind(ssl->rng, ssl->buffers.altKey,
+                (DerBuffer**)&ssl->buffers.altKeyMask);
+        }
+        if (ret != 0) {
+            res = WOLFSSL_FAILURE;
+        }
+    }
+#endif
 #else
-    return check_cert_key(ssl->buffers.certificate, ssl->buffers.key, NULL,
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    wolfssl_priv_der_unblind(ssl->buffers.key, ssl->buffers.keyMask);
+#endif
+    res = check_cert_key(ssl->buffers.certificate, ssl->buffers.key, NULL,
         ssl->heap, ssl->buffers.keyDevId, ssl->buffers.keyLabel,
         ssl->buffers.keyId, INVALID_DEVID, 0, 0);
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    if (res == WOLFSSL_SUCCESS) {
+        int ret = wolfssl_priv_der_blind(ssl->rng, ssl->buffers.key,
+            (DerBuffer**)&ssl->buffers.keyMask);
+        if (ret != 0) {
+            res = WOLFSSL_FAILURE;
+        }
+    }
+#endif
 #endif
+
+    return res;
 }
 #endif /* !NO_CHECK_PRIVATE_KEY */
 
@@ -10726,6 +10805,9 @@ int wolfSSL_set_compression(WOLFSSL* ssl)
             WOLFSSL_MSG("Unloading key");
             ForceZero(ssl->buffers.key->buffer, ssl->buffers.key->length);
             FreeDer(&ssl->buffers.key);
+        #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+            FreeDer(&ssl->buffers.keyMask);
+        #endif
             ssl->buffers.weOwnKey = 0;
         }
 
@@ -10734,6 +10816,9 @@ int wolfSSL_set_compression(WOLFSSL* ssl)
             WOLFSSL_MSG("Unloading alt key");
             ForceZero(ssl->buffers.altKey->buffer, ssl->buffers.altKey->length);
             FreeDer(&ssl->buffers.altKey);
+        #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+            FreeDer(&ssl->buffers.altKeyMask);
+        #endif
             ssl->buffers.weOwnAltKey = 0;
         }
 #endif /* WOLFSSL_DUAL_ALG_CERTS */
@@ -19405,18 +19490,32 @@ void wolfSSL_certs_clear(WOLFSSL* ssl)
 #ifdef WOLFSSL_TLS13
     ssl->buffers.certChainCnt = 0;
 #endif
-    if (ssl->buffers.weOwnKey)
+    if (ssl->buffers.weOwnKey) {
         FreeDer(&ssl->buffers.key);
+    #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+        FreeDer(&ssl->buffers.keyMask);
+    #endif
+    }
     ssl->buffers.key      = NULL;
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    ssl->buffers.keyMask  = NULL;
+#endif
     ssl->buffers.keyType  = 0;
     ssl->buffers.keyId    = 0;
     ssl->buffers.keyLabel = 0;
     ssl->buffers.keySz    = 0;
     ssl->buffers.keyDevId = 0;
 #ifdef WOLFSSL_DUAL_ALG_CERTS
-    if (ssl->buffers.weOwnAltKey)
+    if (ssl->buffers.weOwnAltKey) {
         FreeDer(&ssl->buffers.altKey);
-    ssl->buffers.altKey   = NULL;
+    #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+        FreeDer(&ssl->buffers.altKeyMask);
+    #endif
+    }
+    ssl->buffers.altKey     = NULL;
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    ssl->buffers.altKeyMask = NULL;
+#endif
 #endif /* WOLFSSL_DUAL_ALG_CERTS */
 }
 #endif
@@ -19985,7 +20084,22 @@ WOLFSSL_CTX* wolfSSL_set_SSL_CTX(WOLFSSL* ssl, WOLFSSL_CTX* ctx)
 #ifdef WOLFSSL_TLS13
     ssl->buffers.certChainCnt = ctx->certChainCnt;
 #endif
+#ifndef WOLFSSL_BLIND_PRIVATE_KEY
     ssl->buffers.key      = ctx->privateKey;
+#else
+    if (ctx->privateKey != NULL) {
+        AllocCopyDer(&ssl->buffers.key, ctx->privateKey->buffer,
+            ctx->privateKey->length, ctx->privateKey->type,
+            ctx->privateKey->heap);
+        /* Blind the private key for the SSL with new random mask. */
+        wolfssl_priv_der_unblind(ssl->buffers.key, ctx->privateKeyMask);
+        ret = wolfssl_priv_der_blind(ssl->rng, ssl->buffers.key,
+            &ssl->buffers.keyMask);
+        if (ret != 0) {
+            return ret;
+        }
+    }
+#endif
     ssl->buffers.keyType  = ctx->privateKeyType;
     ssl->buffers.keyId    = ctx->privateKeyId;
     ssl->buffers.keyLabel = ctx->privateKeyLabel;
@@ -20000,7 +20114,22 @@ WOLFSSL_CTX* wolfSSL_set_SSL_CTX(WOLFSSL* ssl, WOLFSSL_CTX* ctx)
     ssl->options.haveFalconSig    = ctx->haveFalconSig;
     ssl->options.haveDilithiumSig = ctx->haveDilithiumSig;
 #ifdef WOLFSSL_DUAL_ALG_CERTS
-    ssl->buffers.altKey     = ctx->altPrivateKey;
+#ifndef WOLFSSL_BLIND_PRIVATE_KEY
+    ssl->buffers.altKey   = ctx->altPrivateKey;
+#else
+    if (ctx->altPrivateKey != NULL) {
+        AllocCopyDer(&ssl->buffers.altkey, ctx->altPrivateKey->buffer,
+            ctx->altPrivateKey->length, ctx->altPrivateKey->type,
+            ctx->altPrivateKey->heap);
+        /* Blind the private key for the SSL with new random mask. */
+        wolfssl_priv_der_unblind(ssl->buffers.altKey, ctx->altPrivateKeyMask);
+        ret = wolfssl_priv_der_blind(ssl->rng, ssl->buffers.altKey,
+            &ssl->buffers.altKeyMask);
+        if (ret != 0) {
+            return ret;
+        }
+    }
+#endif
     ssl->buffers.altKeySz   = ctx->altPrivateKeySz;
     ssl->buffers.altKeyType = ctx->altPrivateKeyType;
 #endif /* WOLFSSL_DUAL_ALG_CERTS */
diff --git a/src/ssl_load.c b/src/ssl_load.c
index 5e011fab0e..f3f6ce3b9b 100644
--- a/src/ssl_load.c
+++ b/src/ssl_load.c
@@ -1243,10 +1243,13 @@ static int ProcessBufferPrivPkcs8Dec(EncryptedInfo* info, DerBuffer* der,
  * @param [in, out] ctx  SSL context object.
  * @param [in, out] ssl  SSL object.
  * @param [in]      der  DER encoding.
+ * @return  0 on success.
  */
-static void ProcessBufferPrivKeyHandleDer(WOLFSSL_CTX* ctx, WOLFSSL* ssl,
+static int ProcessBufferPrivKeyHandleDer(WOLFSSL_CTX* ctx, WOLFSSL* ssl,
     DerBuffer** der, int type)
 {
+    int ret = 0;
+
     (void)type;
 
 #ifdef WOLFSSL_DUAL_ALG_CERTS
@@ -1256,6 +1259,9 @@ static void ProcessBufferPrivKeyHandleDer(WOLFSSL_CTX* ctx, WOLFSSL* ssl,
             /* Dispose of previous key if not context's. */
             if (ssl->buffers.weOwnAltKey) {
                 FreeDer(&ssl->buffers.altKey);
+            #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+                FreeDer(&ssl->buffers.altKeyMask);
+            #endif
             }
             ssl->buffers.altKeyId = 0;
             ssl->buffers.altKeyLabel = 0;
@@ -1286,6 +1292,9 @@ static void ProcessBufferPrivKeyHandleDer(WOLFSSL_CTX* ctx, WOLFSSL* ssl,
         /* Dispose of previous key if not context's. */
         if (ssl->buffers.weOwnKey) {
             FreeDer(&ssl->buffers.key);
+        #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+            FreeDer(&ssl->buffers.keyMask);
+        #endif
         }
         ssl->buffers.keyId = 0;
         ssl->buffers.keyLabel = 0;
@@ -1309,6 +1318,8 @@ static void ProcessBufferPrivKeyHandleDer(WOLFSSL_CTX* ctx, WOLFSSL* ssl,
         wc_MemZero_Add("CTX private key", (*der)->buffer, (*der)->length);
     #endif
     }
+
+    return ret;
 }
 
 /* Decode private key.
@@ -1352,9 +1363,11 @@ static int ProcessBufferPrivateKey(WOLFSSL_CTX* ctx, WOLFSSL* ssl,
 #endif
 
     /* Put the data into the SSL or SSL context object. */
-    ProcessBufferPrivKeyHandleDer(ctx, ssl, &der, type);
-    /* Try to decode the DER data. */
-    ret = ProcessBufferTryDecode(ctx, ssl, der, &algId, heap, type);
+    ret = ProcessBufferPrivKeyHandleDer(ctx, ssl, &der, type);
+    if (ret == 0) {
+        /* Try to decode the DER data. */
+        ret = ProcessBufferTryDecode(ctx, ssl, der, &algId, heap, type);
+    }
 
 #if defined(WOLFSSL_ENCRYPTED_KEYS) && !defined(NO_PWDBASED)
     /* If private key type PKCS8 header wasn't already removed (algId == 0). */
@@ -1369,6 +1382,30 @@ static int ProcessBufferPrivateKey(WOLFSSL_CTX* ctx, WOLFSSL* ssl,
     }
 #endif /* WOLFSSL_ENCRYPTED_KEYS && !NO_PWDBASED */
 
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+#ifdef WOLFSSL_DUAL_ALG_CERTS
+    if (type == ALT_PRIVATEKEY_TYPE) {
+        if (ssl != NULL) {
+            ret = wolfssl_priv_der_blind(ssl->rng, ssl->buffers.altKey,
+                &ssl->buffers.altKeyMask);
+        }
+        else {
+            ret = wolfssl_priv_der_blind(NULL, ctx->altPrivateKey,
+                &ctx->altPrivateKeyMask);
+        }
+    }
+    else
+#endif
+    if (ssl != NULL) {
+        ret = wolfssl_priv_der_blind(ssl->rng, ssl->buffers.key,
+            &ssl->buffers.keyMask);
+    }
+    else {
+        ret = wolfssl_priv_der_blind(NULL, ctx->privateKey,
+            &ctx->privateKeyMask);
+    }
+#endif
+
     /* Check if we were able to determine algorithm id. */
     if ((ret == 0) && (algId == 0)) {
     #ifdef OPENSSL_EXTRA
@@ -4257,6 +4294,9 @@ int wolfSSL_use_PrivateKey_Id(WOLFSSL* ssl, const unsigned char* id,
     /* Dispose of old private key if owned and allocate and copy in id. */
     if (ssl->buffers.weOwnKey) {
         FreeDer(&ssl->buffers.key);
+    #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+        FreeDer(&ssl->buffers.keyMask);
+    #endif
     }
     if (AllocCopyDer(&ssl->buffers.key, id, (word32)sz, PRIVATEKEY_TYPE,
             ssl->heap) != 0) {
@@ -4324,6 +4364,9 @@ int wolfSSL_use_PrivateKey_Label(WOLFSSL* ssl, const char* label, int devId)
     /* Dispose of old private key if owned and allocate and copy in label. */
     if (ssl->buffers.weOwnKey) {
         FreeDer(&ssl->buffers.key);
+    #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+        FreeDer(&ssl->buffers.keyMask);
+    #endif
     }
     if (AllocCopyDer(&ssl->buffers.key, (const byte*)label, (word32)sz,
             PRIVATEKEY_TYPE, ssl->heap) != 0) {
@@ -4366,6 +4409,9 @@ int wolfSSL_use_AltPrivateKey_Id(WOLFSSL* ssl, const unsigned char* id, long sz,
     if (ret == 1) {
         if (ssl->buffers.weOwnAltKey) {
             FreeDer(&ssl->buffers.altKey);
+        #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+            FreeDer(&ssl->buffers.altKeyMask);
+        #endif
         }
         if (AllocDer(&ssl->buffers.altKey, (word32)sz, ALT_PRIVATEKEY_TYPE,
                 ssl->heap) == 0) {
@@ -4409,8 +4455,12 @@ int wolfSSL_use_AltPrivateKey_Label(WOLFSSL* ssl, const char* label, int devId)
 
     if (ret == 1) {
         sz = (word32)XSTRLEN(label) + 1;
-        if (ssl->buffers.weOwnAltKey)
+        if (ssl->buffers.weOwnAltKey) {
             FreeDer(&ssl->buffers.altKey);
+        #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+            FreeDer(&ssl->buffers.altKeyMask);
+        #endif
+        }
         if (AllocDer(&ssl->buffers.altKey, (word32)sz, ALT_PRIVATEKEY_TYPE,
                 ssl->heap) == 0) {
             ret = 0;
diff --git a/src/tls13.c b/src/tls13.c
index 37c5ebdccf..951ca5a34a 100644
--- a/src/tls13.c
+++ b/src/tls13.c
@@ -8803,6 +8803,10 @@ static int SendTls13CertificateVerify(WOLFSSL* ssl)
     WOLFSSL_START(WC_FUNC_CERTIFICATE_VERIFY_SEND);
     WOLFSSL_ENTER("SendTls13CertificateVerify");
 
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    wolfssl_priv_der_unblind(ssl->buffers.key, ssl->buffers.keyMask);
+#endif
+
     ssl->options.buildingMsg = 1;
 
 #if defined(WOLFSSL_RENESAS_TSIP_TLS)
@@ -8855,6 +8859,10 @@ static int SendTls13CertificateVerify(WOLFSSL* ssl)
         case TLS_ASYNC_BEGIN:
         {
             if (ssl->options.sendVerify == SEND_BLANK_CERT) {
+            #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+                wolfssl_priv_der_unblind(ssl->buffers.key,
+                    ssl->buffers.keyMask);
+            #endif
                 return 0;  /* sent blank cert, can't verify */
             }
 
@@ -8915,10 +8923,16 @@ static int SendTls13CertificateVerify(WOLFSSL* ssl)
                     /* If we own it, free key before overriding it. */
                     if (ssl->buffers.weOwnKey) {
                         FreeDer(&ssl->buffers.key);
+                    #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+                        FreeDer(&ssl->buffers.keyMask);
+                    #endif
                     }
 
                     /* Swap keys */
-                    ssl->buffers.key = ssl->buffers.altKey;
+                    ssl->buffers.key     = ssl->buffers.altKey;
+                #ifdef WOLFSSL_BLIND_PRIVATE_KEY
+                    ssl->buffers.keyMask = ssl->buffers.altKeyMask;
+                #endif
                     ssl->buffers.weOwnKey = ssl->buffers.weOwnAltKey;
                 }
 #endif /* WOLFSSL_DUAL_ALG_CERTS */
@@ -9543,6 +9557,15 @@ static int SendTls13CertificateVerify(WOLFSSL* ssl)
     } /* switch(ssl->options.asyncState) */
 
 exit_scv:
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    if (ret == 0) {
+        ret = wolfssl_priv_der_blind(ssl->rng, ssl->buffers.key,
+            &ssl->buffers.keyMask);
+    }
+    else {
+        wolfssl_priv_der_unblind(ssl->buffers.key, ssl->buffers.keyMask);
+    }
+#endif
 
     WOLFSSL_LEAVE("SendTls13CertificateVerify", ret);
     WOLFSSL_END(WC_FUNC_CERTIFICATE_VERIFY_SEND);
diff --git a/wolfcrypt/src/ecc.c b/wolfcrypt/src/ecc.c
index b29c19ecce..a58c239a37 100644
--- a/wolfcrypt/src/ecc.c
+++ b/wolfcrypt/src/ecc.c
@@ -98,6 +98,12 @@ Possible ECC enable options:
  *                      Use this when CPU state can be closely observed by
  *                      attacker.
  *                                                              default: off
+ * WOLFSSL_ECC_BLIND_K
+ *                      Blind the private key k by using a random mask.
+ *                      The private key is never stored unprotected but an
+ *                      unmasked copy is computed and stored each time it is
+ *                      needed.
+ *                                                              default: off
  */
 
 /*
@@ -297,6 +303,53 @@ ECC Curve Sizes:
 
 #endif
 
+#ifdef WOLFSSL_ECC_BLIND_K
+mp_int* ecc_get_k(ecc_key* key)
+{
+    mp_xor_ct(key->k, key->kb, key->dp->size, key->ku);
+    return key->ku;
+}
+void ecc_blind_k(ecc_key* key, mp_int* b)
+{
+    mp_xor_ct(key->k, b, key->dp->size, key->k);
+    mp_xor_ct(key->kb, b, key->dp->size, key->kb);
+}
+int ecc_blind_k_rng(ecc_key* key, WC_RNG* rng)
+{
+    int ret = 0;
+    WC_RNG local_rng;
+
+#ifdef ECC_TIMING_RESISTANT
+    if (rng == NULL) {
+        rng = key->rng;
+    }
+#endif
+    if (rng == NULL) {
+        ret = wc_InitRng(&local_rng);
+        if (ret == 0) {
+            rng = &local_rng;
+        }
+    }
+    if (ret == 0) {
+        ret = mp_rand(key->kb, (key->dp->size + sizeof(mp_digit) - 1) /
+            sizeof(mp_digit), rng);
+        if (ret == 0) {
+            mp_xor_ct(key->k, key->kb, key->dp->size, key->k);
+        }
+    }
+
+    if (rng == &local_rng) {
+        wc_FreeRng(&local_rng);
+    }
+    return ret;
+}
+
+mp_int* wc_ecc_key_get_priv(ecc_key* key)
+{
+    return ecc_get_k(key);
+}
+#endif
+
 /* forward declarations */
 static int  wc_ecc_new_point_ex(ecc_point** point, void* heap);
 static void wc_ecc_del_point_ex(ecc_point* p, void* heap);
@@ -4693,7 +4746,7 @@ int wc_ecc_shared_secret_gen_sync(ecc_key* private_key, ecc_point* point,
                                byte* out, word32* outlen)
 {
     int err = MP_OKAY;
-    mp_int* k = private_key->k;
+    mp_int* k = ecc_get_k(private_key);
 #ifdef HAVE_ECC_CDH
 #ifdef WOLFSSL_SMALL_STACK
     mp_int *k_lcl = NULL;
@@ -4723,7 +4776,7 @@ int wc_ecc_shared_secret_gen_sync(ecc_key* private_key, ecc_point* point,
                 goto errout;
             }
             /* multiply cofactor times private key "k" */
-            err = mp_mul_d(private_key->k, cofactor, k);
+            err = mp_mul_d(ecc_get_k(private_key), cofactor, k);
             if (err != MP_OKAY)
                 goto errout;
         }
@@ -4964,7 +5017,8 @@ static int wc_ecc_shared_secret_gen_async(ecc_key* private_key,
         word32 keySz = private_key->dp->size;
 
         /* sync public key x/y */
-        err = wc_mp_to_bigint_sz(private_key->k, &private_key->k->raw, keySz);
+        err = wc_mp_to_bigint_sz(ecc_get_k(private_key),
+            &ecc_get_k(private_key)->raw, keySz);
         if (err == MP_OKAY)
             err = wc_mp_to_bigint_sz(point->x, &point->x->raw, keySz);
         if (err == MP_OKAY)
@@ -4978,7 +5032,7 @@ static int wc_ecc_shared_secret_gen_async(ecc_key* private_key,
                 NitroxEccGetSize(private_key)*2);
         if (err == MP_OKAY)
             err = NitroxEcdh(private_key,
-                &private_key->k->raw, &point->x->raw, &point->y->raw,
+                &ecc_get_k(private_key)->raw, &point->x->raw, &point->y->raw,
                 private_key->e->raw.buf, &private_key->e->raw.len,
                 &curve->prime->raw);
     #else
@@ -4986,7 +5040,7 @@ static int wc_ecc_shared_secret_gen_async(ecc_key* private_key,
             err = wc_ecc_curve_load(private_key->dp, &curve, ECC_CURVE_FIELD_BF);
         if (err == MP_OKAY)
             err = IntelQaEcdh(&private_key->asyncDev,
-                &private_key->k->raw, &point->x->raw, &point->y->raw,
+                &ecc_get_k(private_key)->raw, &point->x->raw, &point->y->raw,
                 out, outlen,
                 &curve->Af->raw, &curve->Bf->raw, &curve->prime->raw,
                 private_key->dp->cofactor);
@@ -5371,9 +5425,9 @@ static int ecc_make_pub_ex(ecc_key* key, ecc_curve_spec* curve,
         key->type = ECC_PRIVATEKEY_ONLY;
     }
 
-    if ((err == MP_OKAY) && (mp_iszero(key->k) || mp_isneg(key->k) ||
-                                      (mp_cmp(key->k, curve->order) != MP_LT)))
-    {
+    if ((err == MP_OKAY) && (mp_iszero(ecc_get_k(key)) ||
+            mp_isneg(ecc_get_k(key)) ||
+            (mp_cmp(ecc_get_k(key), curve->order) != MP_LT))) {
         err = ECC_PRIV_KEY_E;
     }
 
@@ -5395,10 +5449,10 @@ static int ecc_make_pub_ex(ecc_key* key, ecc_curve_spec* curve,
     if (err == MP_OKAY && key->asyncDev.marker == WOLFSSL_ASYNC_MARKER_ECC) {
         word32 keySz = key->dp->size;
         /* sync private key to raw */
-        err = wc_mp_to_bigint_sz(key->k, &key->k->raw, keySz);
+        err = wc_mp_to_bigint_sz(ecc_get_k(key), &ecc_get_k(key)->raw, keySz);
         if (err == MP_OKAY) {
             err = IntelQaEccPointMul(&key->asyncDev,
-                &key->k->raw, pub->x, pub->y, pub->z,
+                &ecc_get_k(key)->raw, pub->x, pub->y, pub->z,
                 &curve->Gx->raw, &curve->Gy->raw,
                 &curve->Af->raw, &curve->Bf->raw, &curve->prime->raw,
                 key->dp->cofactor);
@@ -5414,25 +5468,25 @@ static int ecc_make_pub_ex(ecc_key* key, ecc_curve_spec* curve,
     else
 #ifndef WOLFSSL_SP_NO_256
     if (key->idx != ECC_CUSTOM_IDX && ecc_sets[key->idx].id == ECC_SECP256R1) {
-        err = sp_ecc_mulmod_base_256(key->k, pub, 1, key->heap);
+        err = sp_ecc_mulmod_base_256(ecc_get_k(key), pub, 1, key->heap);
     }
     else
 #endif /* WOLFSSL_SP_NO_256 */
 #if defined(WOLFSSL_SM2) && defined(WOLFSSL_SP_SM2)
     if (key->idx != ECC_CUSTOM_IDX && ecc_sets[key->idx].id == ECC_SM2P256V1) {
-        err = sp_ecc_mulmod_base_sm2_256(key->k, pub, 1, key->heap);
+        err = sp_ecc_mulmod_base_sm2_256(ecc_get_k(key), pub, 1, key->heap);
     }
     else
 #endif
 #ifdef WOLFSSL_SP_384
     if (key->idx != ECC_CUSTOM_IDX && ecc_sets[key->idx].id == ECC_SECP384R1) {
-        err = sp_ecc_mulmod_base_384(key->k, pub, 1, key->heap);
+        err = sp_ecc_mulmod_base_384(ecc_get_k(key), pub, 1, key->heap);
     }
     else
 #endif
 #ifdef WOLFSSL_SP_521
     if (key->idx != ECC_CUSTOM_IDX && ecc_sets[key->idx].id == ECC_SECP521R1) {
-        err = sp_ecc_mulmod_base_521(key->k, pub, 1, key->heap);
+        err = sp_ecc_mulmod_base_521(ecc_get_k(key), pub, 1, key->heap);
     }
     else
 #endif
@@ -5464,8 +5518,8 @@ static int ecc_make_pub_ex(ecc_key* key, ecc_curve_spec* curve,
         /* make the public key */
         if (err == MP_OKAY) {
             /* Map in a separate call as this should be constant time */
-            err = wc_ecc_mulmod_ex2(key->k, base, pub, curve->Af, curve->prime,
-                                               curve->order, rng, 0, key->heap);
+            err = wc_ecc_mulmod_ex2(ecc_get_k(key), base, pub, curve->Af,
+                                 curve->prime, curve->order, rng, 0, key->heap);
             if (err == MP_MEM) {
                err = MEMORY_E;
             }
@@ -5720,6 +5774,11 @@ static int _ecc_make_key_ex(WC_RNG* rng, int keysize, ecc_key* key,
 
     if (err == SA_SILIB_RET_OK) {
         err = mp_read_unsigned_bin(key->k, ucompressed_key, raw_size);
+#ifdef WOLFSSL_ECC_BLIND_K
+        if (err == MP_OKAY) {
+            err = ecc_blind_k_rng(key, rng);
+        }
+#endif
     }
 
 #elif defined(WOLFSSL_SILABS_SE_ACCEL)
@@ -5771,7 +5830,12 @@ static int _ecc_make_key_ex(WC_RNG* rng, int keysize, ecc_key* key,
         err = xil_mpi_import(key->pubkey.y, key->keyRaw + key->dp->size,
                              key->dp->size, key->heap);
     if (err == 0)
-        err = xil_mpi_import(key->k, key->privKey, key->dp->size, key->heap);
+        err = xil_mpi_import(key->k, key->privKey, key->dp->size,
+                             key->heap);
+#ifdef WOLFSSL_ECC_BLIND_K
+    if (err == 0)
+        err = ecc_blind_k_rng(key, rng);
+#endif
     if (err == 0)
         err = mp_set(key->pubkey.z, 1);
     if (err) {
@@ -5953,6 +6017,11 @@ static int _ecc_make_key_ex(WC_RNG* rng, int keysize, ecc_key* key,
          err = wc_mp_to_bigint(key->pubkey.z, &key->pubkey.z->raw);
 #endif
 
+#ifdef WOLFSSL_ECC_BLIND_K
+    if (err == MP_OKAY)
+        err = ecc_blind_k_rng(key, rng);
+#endif
+
 #endif /* HAVE_ECC_MAKE_PUB */
 
     return err;
@@ -6140,13 +6209,27 @@ int wc_ecc_init_ex(ecc_key* key, void* heap, int devId)
     alt_fp_init(key->pubkey.z);
     key->k = (mp_int*)key->ka;
     alt_fp_init(key->k);
+#ifdef WOLFSSL_ECC_BLIND_K
+    key->kb = (mp_int*)key->kba;
+    key->ku = (mp_int*)key->kia;
+    alt_fp_init(key->kb);
+    alt_fp_init(key->ku);
+#endif
 #else
     ret = mp_init_multi(key->k, key->pubkey.x, key->pubkey.y, key->pubkey.z,
-                                                                    NULL, NULL);
+#ifndef WOLFSSL_ECC_BLIND_K
+                                                                      NULL, NULL
+#else
+                                                                key->kb, key->ku
+#endif
+                        );
     if (ret != MP_OKAY) {
         return MEMORY_E;
     }
 #endif /* ALT_ECC_SIZE */
+#ifdef WOLFSSL_ECC_BLIND_K
+    mp_forcezero(key->kb);
+#endif
 #endif /* WOLFSSL_ATECC508A */
 #if (defined(WOLFSSL_ECDSA_SET_K) || defined(WOLFSSL_ECDSA_SET_K_ONE_LOOP) || \
      defined(WOLFSSL_ECDSA_DETERMINISTIC_K) || \
@@ -6190,6 +6273,10 @@ int wc_ecc_init_ex(ecc_key* key, void* heap, int devId)
 
 #ifdef WOLFSSL_CHECK_MEM_ZERO
     mp_memzero_add("ECC k", key->k);
+#ifdef WOLFSSL_ECC_BLIND_K
+    mp_memzero_add("ECC kb", key->kb);
+    mp_memzero_add("ECC ku", key->ku);
+#endif
 #endif
 
 #if defined(WOLFSSL_XILINX_CRYPT_VERSAL)
@@ -6750,7 +6837,7 @@ static int deterministic_sign_helper(const byte* in, word32 inlen, ecc_key* key)
             /* currently limiting to SHA256 for auto create */
             if (mp_init(key->sign_k) != MP_OKAY ||
                 wc_ecc_gen_deterministic_k(in, inlen,
-                        WC_HASH_TYPE_SHA256, key->k, key->sign_k,
+                        WC_HASH_TYPE_SHA256, ecc_get_k(key), key->sign_k,
                         curve->order, key->heap) != 0) {
                 mp_free(key->sign_k);
                 XFREE(key->sign_k, key->heap, DYNAMIC_TYPE_ECC);
@@ -6769,8 +6856,8 @@ static int deterministic_sign_helper(const byte* in, word32 inlen, ecc_key* key)
     #else
         key->sign_k_set = 0;
         /* currently limiting to SHA256 for auto create */
-        if (wc_ecc_gen_deterministic_k(in, inlen, WC_HASH_TYPE_SHA256, key->k,
-                key->sign_k, curve->order, key->heap) != 0) {
+        if (wc_ecc_gen_deterministic_k(in, inlen, WC_HASH_TYPE_SHA256,
+                ecc_get_k(key), key->sign_k, curve->order, key->heap) != 0) {
             err = ECC_PRIV_KEY_E;
         }
         else {
@@ -6908,15 +6995,18 @@ static int ecc_sign_hash_sw(ecc_key* key, ecc_key* pubkey, WC_RNG* rng,
         if (err != MP_OKAY) break;
 
         if (mp_iszero(r) == MP_NO) {
-            mp_int* ep = pubkey->k;
-            mp_int* kp = pubkey->k;
-            mp_int* x  = key->k;
+            mp_int* kp = ecc_get_k(pubkey);
+            mp_int* ep = kp;
+            mp_int* x  = ecc_get_k(key);
+
+            /* Blind after getting. */
+            ecc_blind_k(key, b);
 
             /* find s = (e + xr)/k
                       = b.(e/k.b + x.r/k.b) */
 
             /* k' = k.b */
-            err = mp_mulmod(pubkey->k, b, curve->order, kp);
+            err = mp_mulmod(kp, b, curve->order, kp);
             if (err != MP_OKAY) break;
 
             /* k' = 1/k.b
@@ -6995,12 +7085,12 @@ static int ecc_sign_hash_sp(const byte* in, word32 inlen, WC_RNG* rng,
             #endif
             if (key->nb_ctx) {
                 return sp_ecc_sign_256_nb(&key->nb_ctx->sp_ctx, in, inlen, rng,
-                    key->k, r, s, sign_k, key->heap);
+                    ecc_get_k(key), r, s, sign_k, key->heap);
             }
             #ifdef WC_ECC_NONBLOCK_ONLY
             do { /* perform blocking call to non-blocking function */
                 err = sp_ecc_sign_256_nb(&nb_ctx.sp_ctx, in, inlen, rng,
-                    key->k, r, s, sign_k, key->heap);
+                    ecc_get_k(key), r, s, sign_k, key->heap);
             } while (err == FP_WOULDBLOCK);
             return err;
             #endif
@@ -7009,8 +7099,8 @@ static int ecc_sign_hash_sp(const byte* in, word32 inlen, WC_RNG* rng,
             {
                 int ret;
                 SAVE_VECTOR_REGISTERS(return _svr_ret;);
-                ret = sp_ecc_sign_256(in, inlen, rng, key->k, r, s, sign_k,
-                                      key->heap);
+                ret = sp_ecc_sign_256(in, inlen, rng, ecc_get_k(key), r, s,
+                                      sign_k, key->heap);
                 RESTORE_VECTOR_REGISTERS();
                 return ret;
             }
@@ -7021,8 +7111,8 @@ static int ecc_sign_hash_sp(const byte* in, word32 inlen, WC_RNG* rng,
         if (ecc_sets[key->idx].id == ECC_SM2P256V1) {
             int ret;
             SAVE_VECTOR_REGISTERS(return _svr_ret;);
-            ret = sp_ecc_sign_sm2_256(in, inlen, rng, key->k, r, s, sign_k,
-                key->heap);
+            ret = sp_ecc_sign_sm2_256(in, inlen, rng, ecc_get_k(key), r, s,
+                                      sign_k, key->heap);
             RESTORE_VECTOR_REGISTERS();
             return ret;
         }
@@ -7035,12 +7125,12 @@ static int ecc_sign_hash_sp(const byte* in, word32 inlen, WC_RNG* rng,
             #endif
             if (key->nb_ctx) {
                 return sp_ecc_sign_384_nb(&key->nb_ctx->sp_ctx, in, inlen, rng,
-                    key->k, r, s, sign_k, key->heap);
+                    ecc_get_k(key), r, s, sign_k, key->heap);
             }
             #ifdef WC_ECC_NONBLOCK_ONLY
             do { /* perform blocking call to non-blocking function */
                 err = sp_ecc_sign_384_nb(&nb_ctx.sp_ctx, in, inlen, rng,
-                    key->k, r, s, sign_k, key->heap);
+                    ecc_get_k(key), r, s, sign_k, key->heap);
             } while (err == FP_WOULDBLOCK);
             return err;
             #endif
@@ -7049,8 +7139,8 @@ static int ecc_sign_hash_sp(const byte* in, word32 inlen, WC_RNG* rng,
             {
                 int ret;
                 SAVE_VECTOR_REGISTERS(return _svr_ret;);
-                ret = sp_ecc_sign_384(in, inlen, rng, key->k, r, s, sign_k,
-                                      key->heap);
+                ret = sp_ecc_sign_384(in, inlen, rng, ecc_get_k(key), r, s,
+                                      sign_k, key->heap);
                 RESTORE_VECTOR_REGISTERS();
                 return ret;
             }
@@ -7065,12 +7155,12 @@ static int ecc_sign_hash_sp(const byte* in, word32 inlen, WC_RNG* rng,
             #endif
             if (key->nb_ctx) {
                 return sp_ecc_sign_521_nb(&key->nb_ctx->sp_ctx, in, inlen, rng,
-                    key->k, r, s, sign_k, key->heap);
+                    ecc_get_k(key), r, s, sign_k, key->heap);
             }
             #ifdef WC_ECC_NONBLOCK_ONLY
             do { /* perform blocking call to non-blocking function */
                 err = sp_ecc_sign_521_nb(&nb_ctx.sp_ctx, in, inlen, rng,
-                    key->k, r, s, sign_k, key->heap);
+                    ecc_get_k(key), r, s, sign_k, key->heap);
             } while (err == FP_WOULDBLOCK);
             return err;
             #endif
@@ -7079,8 +7169,8 @@ static int ecc_sign_hash_sp(const byte* in, word32 inlen, WC_RNG* rng,
             {
                 int ret;
                 SAVE_VECTOR_REGISTERS(return _svr_ret;);
-                ret = sp_ecc_sign_521(in, inlen, rng, key->k, r, s, sign_k,
-                                      key->heap);
+                ret = sp_ecc_sign_521(in, inlen, rng, ecc_get_k(key), r, s,
+                                      sign_k, key->heap);
                 RESTORE_VECTOR_REGISTERS();
                 return ret;
             }
@@ -7303,7 +7393,8 @@ int wc_ecc_sign_hash_ex(const byte* in, word32 inlen, WC_RNG* rng,
            if (err == MP_OKAY)
                err = wc_mp_to_bigint_sz(e, &e->raw, keySz);
            if (err == MP_OKAY)
-               err = wc_mp_to_bigint_sz(key->k, &key->k->raw, keySz);
+               err = wc_mp_to_bigint_sz(ecc_get_k(key), &ecc_get_k(key)->raw,
+                  keySz);
            if (err == MP_OKAY)
                err = wc_ecc_gen_k(rng, key->dp->size, k, curve->order);
            if (err == MP_OKAY)
@@ -7311,14 +7402,15 @@ int wc_ecc_sign_hash_ex(const byte* in, word32 inlen, WC_RNG* rng,
 
        #ifdef HAVE_CAVIUM_V
            if (err == MP_OKAY)
-               err = NitroxEcdsaSign(key, &e->raw, &key->k->raw, &k->raw,
-                &r->raw, &s->raw, &curve->prime->raw, &curve->order->raw);
+               err = NitroxEcdsaSign(key, &e->raw, &ecc_get_k(key)->raw,
+                  &k->raw, &r->raw, &s->raw, &curve->prime->raw,
+                  &curve->order->raw);
        #else
            if (err == MP_OKAY)
-               err = IntelQaEcdsaSign(&key->asyncDev, &e->raw, &key->k->raw,
-                  &k->raw, &r->raw, &s->raw, &curve->Af->raw, &curve->Bf->raw,
-                  &curve->prime->raw, &curve->order->raw, &curve->Gx->raw,
-                  &curve->Gy->raw);
+               err = IntelQaEcdsaSign(&key->asyncDev, &e->raw,
+                  &ecc_get_k(key)->raw, &k->raw, &r->raw, &s->raw,
+                  &curve->Af->raw, &curve->Bf->raw, &curve->prime->raw,
+                  &curve->order->raw, &curve->Gx->raw, &curve->Gy->raw);
        #endif
 
        #ifndef HAVE_CAVIUM_V
@@ -7820,6 +7912,16 @@ int wc_ecc_free(ecc_key* key)
     if (key->k)
 #endif
         mp_forcezero(key->k);
+#ifdef WOLFSSL_ECC_BLIND_K
+#ifdef ALT_ECC_SIZE
+    if (key->kb)
+#endif
+        mp_forcezero(key->kb);
+#ifdef ALT_ECC_SIZE
+    if (key->ku)
+#endif
+        mp_forcezero(key->ku);
+#endif
 
 #ifdef WOLFSSL_CUSTOM_CURVES
     if (key->deallocSet && key->dp != NULL)
@@ -9892,7 +9994,7 @@ static int ecc_check_privkey_gen(ecc_key* key, mp_int* a, mp_int* prime)
 #ifndef WOLFSSL_SP_NO_256
     if (key->idx != ECC_CUSTOM_IDX && ecc_sets[key->idx].id == ECC_SECP256R1) {
         if (err == MP_OKAY) {
-            err = sp_ecc_mulmod_base_256(key->k, res, 1, key->heap);
+            err = sp_ecc_mulmod_base_256(ecc_get_k(key), res, 1, key->heap);
         }
     }
     else
@@ -9900,7 +10002,7 @@ static int ecc_check_privkey_gen(ecc_key* key, mp_int* a, mp_int* prime)
 #if defined(WOLFSSL_SM2) && defined(WOLFSSL_SP_SM2)
     if (key->idx != ECC_CUSTOM_IDX && ecc_sets[key->idx].id == ECC_SM2P256V1) {
         if (err == MP_OKAY) {
-            err = sp_ecc_mulmod_base_sm2_256(key->k, res, 1, key->heap);
+            err = sp_ecc_mulmod_base_sm2_256(ecc_get_k(key), res, 1, key->heap);
         }
     }
     else
@@ -9908,7 +10010,7 @@ static int ecc_check_privkey_gen(ecc_key* key, mp_int* a, mp_int* prime)
 #ifdef WOLFSSL_SP_384
     if (key->idx != ECC_CUSTOM_IDX && ecc_sets[key->idx].id == ECC_SECP384R1) {
         if (err == MP_OKAY) {
-            err = sp_ecc_mulmod_base_384(key->k, res, 1, key->heap);
+            err = sp_ecc_mulmod_base_384(ecc_get_k(key), res, 1, key->heap);
         }
     }
     else
@@ -9916,7 +10018,7 @@ static int ecc_check_privkey_gen(ecc_key* key, mp_int* a, mp_int* prime)
 #ifdef WOLFSSL_SP_521
     if (key->idx != ECC_CUSTOM_IDX && ecc_sets[key->idx].id == ECC_SECP521R1) {
         if (err == MP_OKAY) {
-            err = sp_ecc_mulmod_base_521(key->k, res, 1, key->heap);
+            err = sp_ecc_mulmod_base_521(ecc_get_k(key), res, 1, key->heap);
         }
     }
     else
@@ -9969,12 +10071,12 @@ static int ecc_check_privkey_gen(ecc_key* key, mp_int* a, mp_int* prime)
 #else
 #ifdef ECC_TIMING_RESISTANT
         if (err == MP_OKAY)
-            err = wc_ecc_mulmod_ex2(key->k, base, res, a, prime, curve->order,
-                                                        key->rng, 1, key->heap);
+            err = wc_ecc_mulmod_ex2(ecc_get_k(key), base, res, a, prime,
+                                          curve->order, key->rng, 1, key->heap);
 #else
         if (err == MP_OKAY)
-            err = wc_ecc_mulmod_ex2(key->k, base, res, a, prime, curve->order,
-                                                            NULL, 1, key->heap);
+            err = wc_ecc_mulmod_ex2(ecc_get_k(key), base, res, a, prime,
+                                              curve->order, NULL, 1, key->heap);
 #endif
 #endif /* WOLFSSL_KCAPI_ECC */
     }
@@ -10245,31 +10347,31 @@ static int _ecc_validate_public_key(ecc_key* key, int partial, int priv)
 #ifndef WOLFSSL_SP_NO_256
     if (key->idx != ECC_CUSTOM_IDX && ecc_sets[key->idx].id == ECC_SECP256R1) {
         return sp_ecc_check_key_256(key->pubkey.x, key->pubkey.y,
-            key->type == ECC_PRIVATEKEY ? key->k : NULL, key->heap);
+            key->type == ECC_PRIVATEKEY ? ecc_get_k(key) : NULL, key->heap);
     }
 #endif
 #if defined(WOLFSSL_SM2) && defined(WOLFSSL_SP_SM2)
     if (key->idx != ECC_CUSTOM_IDX && ecc_sets[key->idx].id == ECC_SM2P256V1) {
         return sp_ecc_check_key_sm2_256(key->pubkey.x, key->pubkey.y,
-            key->type == ECC_PRIVATEKEY ? key->k : NULL, key->heap);
+            key->type == ECC_PRIVATEKEY ? ecc_get_k(key) : NULL, key->heap);
     }
 #endif
 #ifdef WOLFSSL_SP_384
     if (key->idx != ECC_CUSTOM_IDX && ecc_sets[key->idx].id == ECC_SECP384R1) {
         return sp_ecc_check_key_384(key->pubkey.x, key->pubkey.y,
-            key->type == ECC_PRIVATEKEY ? key->k : NULL, key->heap);
+            key->type == ECC_PRIVATEKEY ? ecc_get_k(key) : NULL, key->heap);
     }
 #endif
 #ifdef WOLFSSL_SP_521
     if (key->idx != ECC_CUSTOM_IDX && ecc_sets[key->idx].id == ECC_SECP521R1) {
         return sp_ecc_check_key_521(key->pubkey.x, key->pubkey.y,
-            key->type == ECC_PRIVATEKEY ? key->k : NULL, key->heap);
+            key->type == ECC_PRIVATEKEY ? ecc_get_k(key) : NULL, key->heap);
     }
 #endif
 #if defined(WOLFSSL_SP_1024) && defined(WOLFCRYPT_HAVE_SAKKE)
     if (key->idx != ECC_CUSTOM_IDX && ecc_sets[key->idx].id == ECC_SAKKE_1) {
         return sp_ecc_check_key_1024(key->pubkey.x, key->pubkey.y,
-            key->type == ECC_PRIVATEKEY ? key->k : NULL, key->heap);
+            key->type == ECC_PRIVATEKEY ? ecc_get_k(key) : NULL, key->heap);
     }
 #endif
 #endif
@@ -10380,8 +10482,8 @@ static int _ecc_validate_public_key(ecc_key* key, int partial, int priv)
         /* SP 800-56Ar3, section 5.6.2.1.2 */
         /* private keys must be in the range [1, n-1] */
         if ((err == MP_OKAY) && (key->type == ECC_PRIVATEKEY) &&
-            (mp_iszero(key->k) || mp_isneg(key->k) ||
-            (mp_cmp(key->k, curve->order) != MP_LT))
+            (mp_iszero(ecc_get_k(key)) || mp_isneg(ecc_get_k(key)) ||
+            (mp_cmp(ecc_get_k(key), curve->order) != MP_LT))
         #ifdef WOLFSSL_KCAPI_ECC
             && key->handle == NULL
         #endif
@@ -10466,12 +10568,26 @@ int wc_ecc_import_x963_ex(const byte* in, word32 inLen, ecc_key* key,
         alt_fp_init(key->pubkey.z);
         key->k = (mp_int*)key->ka;
         alt_fp_init(key->k);
+    #ifdef WOLFSSL_ECC_BLIND_K
+        key->kb = (mp_int*)key->kba;
+        key->ku = (mp_int*)key->kua;
+        alt_fp_init(key->kb);
+        alt_fp_init(key->ku);
+    #endif
     #else
-        err = mp_init_multi(key->k,
-                    key->pubkey.x, key->pubkey.y, key->pubkey.z, NULL, NULL);
+        err = mp_init_multi(key->k, key->pubkey.x, key->pubkey.y, key->pubkey.z,
+    #ifndef WOLFSSL_ECC_BLIND_K
+                                                                      NULL, NULL
+    #else
+                                                                key->kb, key->ku
+    #endif
+                            );
     #endif
     if (err != MP_OKAY)
         return MEMORY_E;
+#ifdef WOLFSSL_ECC_BLIND_K
+    mp_forcezero(key->kb);
+#endif
 
     SAVE_VECTOR_REGISTERS(return _svr_ret;);
 
@@ -10780,7 +10896,7 @@ int wc_ecc_export_ex(ecc_key* key, byte* qx, word32* qxLen,
                 return BUFFER_E;
             }
 
-            err = wc_export_int(key->k, d, dLen, keySz + WC_CAAM_MAC_SZ,
+            err = wc_export_int(ecc_get_k(key), d, dLen, keySz + WC_CAAM_MAC_SZ,
                 encType);
             *dLen = keySz + WC_CAAM_MAC_SZ;
         }
@@ -10802,7 +10918,7 @@ int wc_ecc_export_ex(ecc_key* key, byte* qx, word32* qxLen,
         else
     #endif
         {
-            err = wc_export_int(key->k, d, dLen, keySz, encType);
+            err = wc_export_int(ecc_get_k(key), d, dLen, keySz, encType);
             if (err != MP_OKAY)
                 return err;
         }
@@ -10937,6 +11053,11 @@ int wc_ecc_import_private_key_ex(const byte* priv, word32 privSz,
         }
 
         ret = mp_read_unsigned_bin(key->k, priv, privSz);
+    #ifdef WOLFSSL_ECC_BLIND_K
+        if (ret == MP_OKAY) {
+            err = ecc_blind_k_rng(key, NULL);
+        }
+    #endif
     }
 #elif defined(WOLFSSL_QNX_CAAM) || defined(WOLFSSL_IMXRT1170_CAAM)
     if ((wc_ecc_size(key) + WC_CAAM_MAC_SZ) == (int)privSz) {
@@ -10968,11 +11089,21 @@ int wc_ecc_import_private_key_ex(const byte* priv, word32 privSz,
     #else
         key->blackKey = CAAM_BLACK_KEY_CCM;
         ret = mp_read_unsigned_bin(key->k, priv, privSz);
+    #ifdef WOLFSSL_ECC_BLIND_K
+        if (ret == MP_OKAY) {
+            err = ecc_blind_k_rng(key, NULL);
+        }
+    #endif
     #endif
     }
     else {
         key->blackKey = 0;
         ret = mp_read_unsigned_bin(key->k, priv, privSz);
+    #ifdef WOLFSSL_ECC_BLIND_K
+        if (ret == MP_OKAY) {
+            err = ecc_blind_k_rng(key, NULL);
+        }
+    #endif
 
         /* If using AES-ECB encrypted black keys check here if key is valid,
          * if not valid than assume is an encrypted key. A public key is needed
@@ -11001,8 +11132,8 @@ int wc_ecc_import_private_key_ex(const byte* priv, word32 privSz,
 
     ret = mp_read_unsigned_bin(key->k, priv, privSz);
 #ifdef HAVE_WOLF_BIGINT
-    if (ret == 0 &&
-                  wc_bigint_from_unsigned_bin(&key->k->raw, priv, privSz) != 0) {
+    if (ret == 0 && wc_bigint_from_unsigned_bin(&key->k->raw, priv,
+                                                                 privSz) != 0) {
         mp_clear(key->k);
         ret = ASN_GETINT_E;
     }
@@ -11044,6 +11175,11 @@ int wc_ecc_import_private_key_ex(const byte* priv, word32 privSz,
     #endif
     }
 #endif /* WOLFSSL_VALIDATE_ECC_IMPORT */
+#ifdef WOLFSSL_ECC_BLIND_K
+    if (ret == 0) {
+        ret = ecc_blind_k_rng(key, NULL);
+    }
+#endif
 
 #endif /* WOLFSSL_CRYPTOCELL */
 
@@ -11236,12 +11372,26 @@ static int wc_ecc_import_raw_private(ecc_key* key, const char* qx,
     alt_fp_init(key->pubkey.z);
     key->k = (mp_int*)key->ka;
     alt_fp_init(key->k);
+#ifdef WOLFSSL_ECC_BLIND_K
+    key->kb = (mp_int*)key->kba;
+    key->ku = (mp_int*)key->kua;
+    alt_fp_init(key->kb);
+    alt_fp_init(key->ku);
+#endif
 #else
     err = mp_init_multi(key->k, key->pubkey.x, key->pubkey.y, key->pubkey.z,
-                                                                  NULL, NULL);
+#ifndef WOLFSSL_ECC_BLIND_K
+                                                                      NULL, NULL
+#else
+                                                                key->kb, key->ku
+#endif
+                        );
 #endif
     if (err != MP_OKAY)
         return MEMORY_E;
+#ifdef WOLFSSL_ECC_BLIND_K
+    mp_forcezero(key->kb);
+#endif
 
     /* read Qx */
     if (err == MP_OKAY) {
@@ -11388,6 +11538,11 @@ static int wc_ecc_import_raw_private(ecc_key* key, const char* qx,
                 err = wc_export_int(key->k, &keyRaw[0], &keySz, keySz,
                     WC_TYPE_UNSIGNED_BIN);
             }
+        #ifdef WOLFSSL_ECC_BLIND_K
+            if (err == 0) {
+                err = ecc_blind_k_rng(key, NULL);
+            }
+        #endif
 
             if (err == MP_OKAY) {
                 /* Create private key from external key buffer*/
@@ -11419,12 +11574,17 @@ static int wc_ecc_import_raw_private(ecc_key* key, const char* qx,
                         (word32)key->dp->size);
                 }
             }
+        #ifdef WOLFSSL_ECC_BLIND_K
+            if (err == 0) {
+                err = ecc_blind_k_rng(key, NULL);
+            }
+        #endif
 #if defined(WOLFSSL_XILINX_CRYPT_VERSAL)
             if (err == MP_OKAY) {
                 const word32 key_size = key->dp->size;
                 word32 buf_size = key_size;
-                err = wc_export_int(key->k, key->privKey,
-                                    &buf_size, key_size, WC_TYPE_UNSIGNED_BIN);
+                err = wc_export_int(key, key->privKey, &buf_size, key_size,
+                                    WC_TYPE_UNSIGNED_BIN);
                 mp_reverse(key->privKey, key_size);
             }
 #endif
diff --git a/wolfcrypt/src/sp_int.c b/wolfcrypt/src/sp_int.c
index 83a1306b59..3a6884a337 100644
--- a/wolfcrypt/src/sp_int.c
+++ b/wolfcrypt/src/sp_int.c
@@ -8097,6 +8097,27 @@ int sp_submod_ct(const sp_int* a, const sp_int* b, const sp_int* m, sp_int* r)
 }
 #endif /* WOLFSSL_SP_MATH_ALL && HAVE_ECC */
 
+#if defined(WOLFSSL_SP_MATH_ALL) && defined(HAVE_ECC) && \
+    defined(WOLFSSL_ECC_BLIND_K)
+void sp_xor_ct(const sp_int* a, const sp_int* b, int len, sp_int* r)
+{
+    if ((a != NULL) && (b != NULL) && (r != NULL)) {
+        unsigned int i;
+
+        r->used = (len * 8 + SP_WORD_SIZE - 1) / SP_WORD_SIZE;
+        for (i = 0; i < r->used; i++) {
+            r->dp[i] = a->dp[i] ^ b->dp[i];
+        }
+        i = (len * 8) % SP_WORD_SIZE;
+        if (i > 0) {
+            r->dp[r->used - 1] &= ((sp_int_digit)1 << i) - 1;
+        }
+        /* Remove leading zeros. */
+        sp_clamp_ct(r);
+    }
+}
+#endif
+
 /********************
  * Shifting functoins
  ********************/
diff --git a/wolfcrypt/src/wolfmath.c b/wolfcrypt/src/wolfmath.c
index 11e85cd74b..df5f0f85ff 100644
--- a/wolfcrypt/src/wolfmath.c
+++ b/wolfcrypt/src/wolfmath.c
@@ -167,7 +167,8 @@ int get_rand_digit(WC_RNG* rng, mp_digit* d)
     return wc_RNG_GenerateBlock(rng, (byte*)d, sizeof(mp_digit));
 }
 
-#if defined(WC_RSA_BLINDING) || defined(WOLFCRYPT_HAVE_SAKKE)
+#if defined(WC_RSA_BLINDING) || defined(WOLFCRYPT_HAVE_SAKKE) || \
+    defined(WOLFSSL_ECC_BLIND_K)
 int mp_rand(mp_int* a, int digits, WC_RNG* rng)
 {
     int ret = 0;
@@ -221,7 +222,7 @@ int mp_rand(mp_int* a, int digits, WC_RNG* rng)
 
     return ret;
 }
-#endif /* WC_RSA_BLINDING || WOLFCRYPT_HAVE_SAKKE */
+#endif /* WC_RSA_BLINDING || WOLFCRYPT_HAVE_SAKKE || WOLFSSL_ECC_BLIND_K */
 #endif /* !WC_NO_RNG */
 
 #if defined(HAVE_ECC) || defined(WOLFSSL_EXPORT_INT)
diff --git a/wolfssl/internal.h b/wolfssl/internal.h
index 28b72877b4..c2d412986a 100644
--- a/wolfssl/internal.h
+++ b/wolfssl/internal.h
@@ -2180,6 +2180,11 @@ WOLFSSL_LOCAL int  CreateDevPrivateKey(void** pkey, byte* data, word32 length,
                                        int hsType, int label, int id,
                                        void* heap, int devId);
 #endif
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+WOLFSSL_LOCAL int wolfssl_priv_der_blind(WC_RNG* rng, DerBuffer* key,
+    DerBuffer** mask);
+WOLFSSL_LOCAL void wolfssl_priv_der_unblind(DerBuffer* key, DerBuffer* mask);
+#endif
 WOLFSSL_LOCAL int  DecodePrivateKey(WOLFSSL *ssl, word32* length);
 #ifdef WOLFSSL_DUAL_ALG_CERTS
 WOLFSSL_LOCAL int  DecodeAltPrivateKey(WOLFSSL *ssl, word32* length);
@@ -3574,6 +3579,9 @@ struct WOLFSSL_CTX {
     int         certChainCnt;
 #endif
     DerBuffer*  privateKey;
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    DerBuffer*  privateKeyMask;             /* Mask of private key DER. */
+#endif
     byte        privateKeyType;
     byte        privateKeyId:1;
     byte        privateKeyLabel:1;
@@ -3582,6 +3590,9 @@ struct WOLFSSL_CTX {
 
 #ifdef WOLFSSL_DUAL_ALG_CERTS
     DerBuffer*  altPrivateKey;
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    DerBuffer*  altPrivateKeyMask;          /* Mask of alt private key DER. */
+#endif
     byte        altPrivateKeyType;
     byte        altPrivateKeyId:1;
     byte        altPrivateKeyLabel:1;
@@ -4553,6 +4564,9 @@ typedef struct Buffers {
 #ifndef NO_CERTS
     DerBuffer*      certificate;           /* WOLFSSL_CTX owns, unless we own */
     DerBuffer*      key;                   /* WOLFSSL_CTX owns, unless we own */
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    DerBuffer*      keyMask;               /* Mask of private key DER. */
+#endif
     byte            keyType;               /* Type of key */
     byte            keyId:1;               /* Key data is an id not data */
     byte            keyLabel:1;            /* Key data is a label not data */
@@ -4560,6 +4574,9 @@ typedef struct Buffers {
     int             keyDevId;              /* Device Id for key */
 #ifdef WOLFSSL_DUAL_ALG_CERTS
     DerBuffer*      altKey;                /* WOLFSSL_CTX owns, unless we own */
+#ifdef WOLFSSL_BLIND_PRIVATE_KEY
+    DerBuffer*      altKeyMask;            /* Mask of alt private key DER. */
+#endif
     byte            altKeyType;            /* Type of alt key */
     byte            altKeyId:1;            /* Key data is an id not data */
     byte            altKeyLabel:1;         /* Key data is a label not data */
diff --git a/wolfssl/wolfcrypt/ecc.h b/wolfssl/wolfcrypt/ecc.h
index 73f2fa5602..48a43f63c4 100644
--- a/wolfssl/wolfcrypt/ecc.h
+++ b/wolfssl/wolfcrypt/ecc.h
@@ -501,6 +501,17 @@ struct ecc_key {
     mp_int*   k;
     alt_fp_int ka[1];
 #endif
+#ifdef WOLFSSL_ECC_BLIND_K
+#ifndef ALT_ECC_SIZE
+    mp_int    kb[1];
+    mp_int    ku[1];
+#else
+    mp_int*   kb;
+    mp_int*   ku;
+    alt_fp_int kba[1];
+    alt_fp_int kua[1];
+#endif
+#endif
 
 #ifdef WOLFSSL_CAAM
     word32 blackKey;     /* address of key encrypted and in secure memory */
@@ -598,7 +609,20 @@ struct ecc_key {
 #endif
 };
 
-#define wc_ecc_key_get_priv(key) ((key)->k)
+#ifndef WOLFSSL_ECC_BLIND_K
+#define ecc_get_k(key)              (key)->k
+#define ecc_blind_k(key, b)         (void)b
+#define ecc_blind_k_rng(key, rng)   0
+
+#define wc_ecc_key_get_priv(key)    (key)->k
+#else
+mp_int* ecc_get_k(ecc_key* key);
+void ecc_blind_k(ecc_key* key, mp_int* b);
+int ecc_blind_k_rng(ecc_key* key, WC_RNG* rng);
+
+WOLFSSL_API mp_int* wc_ecc_key_get_priv(ecc_key* key);
+#endif
+
 #define WOLFSSL_HAVE_ECC_KEY_GET_PRIV
 
 
diff --git a/wolfssl/wolfcrypt/sp_int.h b/wolfssl/wolfcrypt/sp_int.h
index cf7b8f2894..514b7110fd 100644
--- a/wolfssl/wolfcrypt/sp_int.h
+++ b/wolfssl/wolfcrypt/sp_int.h
@@ -996,6 +996,9 @@ MP_API int sp_submod_ct(const sp_int* a, const sp_int* b, const sp_int* m,
 MP_API int sp_addmod_ct(const sp_int* a, const sp_int* b, const sp_int* m,
     sp_int* r);
 #endif
+#if defined(WOLFSSL_SP_MATH_ALL) && defined(HAVE_ECC)
+MP_API void sp_xor_ct(const sp_int* a, const sp_int* b, int len, sp_int* r);
+#endif
 
 MP_API int sp_lshd(sp_int* a, int s);
 #ifdef WOLFSSL_SP_MATH_ALL
@@ -1144,6 +1147,7 @@ WOLFSSL_LOCAL void sp_memzero_check(sp_int* sp);
 #define mp_submod                           sp_submod
 #define mp_addmod_ct                        sp_addmod_ct
 #define mp_submod_ct                        sp_submod_ct
+#define mp_xor_ct                           sp_xor_ct
 #define mp_lshd                             sp_lshd
 #define mp_rshd                             sp_rshd
 #define mp_div                              sp_div