diff --git a/src/main/java/it/gov/pagopa/payhub/auth/service/a2a/legacy/ValidateJWTLegacyService.java b/src/main/java/it/gov/pagopa/payhub/auth/service/a2a/legacy/ValidateJWTLegacyService.java
index d72cf9e..f2af8f0 100644
--- a/src/main/java/it/gov/pagopa/payhub/auth/service/a2a/legacy/ValidateJWTLegacyService.java
+++ b/src/main/java/it/gov/pagopa/payhub/auth/service/a2a/legacy/ValidateJWTLegacyService.java
@@ -18,17 +18,16 @@
 public class ValidateJWTLegacyService {
 	public static final String TOKEN_TYPE_A2A = "a2a";
 
-	private final A2AClientLegacyPropConfig a2AClientLegacyPropConfig;
 	private final JWTValidator jwtValidator;
+	private final Map<String, PublicKey> clientApplicationsPublicKeyMap;
 
 	public ValidateJWTLegacyService(A2AClientLegacyPropConfig a2AClientLegacyPropConfig, JWTValidator jwtValidator) {
-		this.a2AClientLegacyPropConfig = a2AClientLegacyPropConfig;
+		this.clientApplicationsPublicKeyMap = a2AClientLegacyPropConfig.getPublicKeysAsMap();
 		this.jwtValidator = jwtValidator;
 	}
 
 	public Pair<String, Map<String, Claim>> validate(String token) {
-		Map<String, PublicKey> clientApplicationsPublicKeyMap = a2AClientLegacyPropConfig.getPublicKeysAsMap();
-		Pair<String, Map<String, Claim>> claims = validateToken(clientApplicationsPublicKeyMap, token);
+		Pair<String, Map<String, Claim>> claims = validateToken(token);
 		validateM2MType(claims.getRight());
 		validateClaims(claims.getRight());
 
@@ -53,14 +52,16 @@ private void validateClaims(Map<String, Claim> claims) {
 		}
 	}
 
-	private Pair<String, Map<String, Claim>> validateToken(Map<String, PublicKey> clientApplicationsPublicKeyMap, String token) {
-		try {
-			return clientApplicationsPublicKeyMap.keySet().stream()
-				.map(key -> Pair.of(key, jwtValidator.validate(token, clientApplicationsPublicKeyMap.get(key))))
-				.findFirst()
-				.orElseThrow(() -> new InvalidTokenException("Invalid token for A2A call"));
-		} catch (Exception e) {
-			return null;
+	private Pair<String, Map<String, Claim>> validateToken(String token) {
+		for (String key : clientApplicationsPublicKeyMap.keySet()) {
+			PublicKey publicKey = clientApplicationsPublicKeyMap.get(key);
+			try {
+				Map<String, Claim> claims = jwtValidator.validate(token, publicKey);
+				return Pair.of(key, claims);
+			} catch (Exception e) {
+				log.debug("continue cycling - validation failed with key {}", key);
+			}
 		}
+		throw new InvalidTokenException("Invalid token for A2A call");
 	}
 }
diff --git a/src/test/java/it/gov/pagopa/payhub/auth/service/a2a/legacy/ValidateJWTLegacyServiceTest.java b/src/test/java/it/gov/pagopa/payhub/auth/service/a2a/legacy/ValidateJWTLegacyServiceTest.java
index 9275b3f..73ecd6f 100644
--- a/src/test/java/it/gov/pagopa/payhub/auth/service/a2a/legacy/ValidateJWTLegacyServiceTest.java
+++ b/src/test/java/it/gov/pagopa/payhub/auth/service/a2a/legacy/ValidateJWTLegacyServiceTest.java
@@ -31,24 +31,27 @@ class ValidateJWTLegacyServiceTest {
 	@Mock
 	private JWTValidator jwtValidatorMock;
 	private ValidateJWTLegacyService service;
-	private KeyPair keyPair;
-
+	private KeyPair keyPair1;
+	private KeyPair keyPair2;
 
 	@BeforeEach
 	void setup() throws Exception {
+		keyPair1 = JWTValidatorUtils.generateKeyPair();
+		keyPair2 = JWTValidatorUtils.generateKeyPair();
+		Map<String, PublicKey> publicKeyMap = Map.of(
+			"A2A-IPA_TEST_1", keyPair1.getPublic(),
+			"A2A-IPA_TEST_2", keyPair2.getPublic());
+		when(a2AClientLegacyPropConfig.getPublicKeysAsMap()).thenReturn(publicKeyMap);
 		service = new ValidateJWTLegacyService(a2AClientLegacyPropConfig, jwtValidatorMock);
-		keyPair = JWTValidatorUtils.generateKeyPair();
 	}
 
 	@Test
 	void GivenValidTokenThenOk() {
-		String appName = "A2A-IPA_TEST_1";
-		PublicKey publicKey = keyPair.getPublic();
-		String token = JWTValidatorUtils.generateLegacyToken(keyPair, "a2a", Instant.now(), Instant.now().plusSeconds(3_600_000L), "jti");
-		when(a2AClientLegacyPropConfig.getPublicKeysAsMap()).thenReturn(Map.of(appName, publicKey));
+		String appName = "A2A-IPA_TEST_2";
+		String token = JWTValidatorUtils.generateLegacyToken(keyPair2, "a2a", Instant.now(), Instant.now().plusSeconds(3_600_000L), "jti");
 
 		Map<String, Claim> claimsMap = JWT.decode(token).getClaims();
-		Mockito.when(jwtValidatorMock.validate(token, publicKey)).thenReturn(claimsMap);
+		Mockito.when(jwtValidatorMock.validate(token, keyPair2.getPublic())).thenReturn(claimsMap);
 
 		Pair<String, Map<String, Claim>> result = service.validate(token);
 
@@ -57,18 +60,18 @@ void GivenValidTokenThenOk() {
 
 	@Test
 	void GivenInvalidTokenThenInvalidTokenException() {
-		String appName = "A2A-IPA_TEST_1";
-		PublicKey publicKey = keyPair.getPublic();
-		String token = "invalidToken";
-		when(a2AClientLegacyPropConfig.getPublicKeysAsMap()).thenReturn(Map.of(appName, publicKey));
+		String token = JWTValidatorUtils.generateLegacyToken(keyPair1, "a2a", Instant.now(), Instant.now().plusSeconds(3_600_000L), "jti");
+
+		Map<String, Claim> claimsMap = JWT.decode(token).getClaims();
+		Mockito.when(jwtValidatorMock.validate(token, keyPair2.getPublic())).thenReturn(claimsMap);
 
-		assertThrows(Exception.class, () -> service.validate(token), "given an invalid token");
+		assertThrows(Exception.class, () -> service.validate("invalidToken"), "given an invalid token");
 	}
 
 	@Test
 	void GivenNonM2MAuthTokenThenInvalidTokenException() {
-		PublicKey publicKey = keyPair.getPublic();
-		String token = JWTValidatorUtils.generateLegacyToken(keyPair, "notA2A", Instant.now(), Instant.now().plusSeconds(3_600L), "jwtId");
+		PublicKey publicKey = keyPair2.getPublic();
+		String token = JWTValidatorUtils.generateLegacyToken(keyPair2, "notA2A", Instant.now(), Instant.now().plusSeconds(3_600L), "jwtId");
 		when(a2AClientLegacyPropConfig.getPublicKeysAsMap()).thenReturn(Map.of("A2A-IPA_TEST_1", publicKey));
 
 		Map<String, Claim> claimsMap = JWT.decode(token).getClaims();
@@ -79,8 +82,8 @@ void GivenNonM2MAuthTokenThenInvalidTokenException() {
 
 	@Test
 	void GivenInvalidIatThenInvalidTokenException() {
-		PublicKey publicKey = keyPair.getPublic();
-		String token = JWTValidatorUtils.generateLegacyToken(keyPair, "a2a", Instant.now().plusSeconds(3_600L), Instant.now().plusSeconds(3_600_000L), "jwtId");
+		PublicKey publicKey = keyPair2.getPublic();
+		String token = JWTValidatorUtils.generateLegacyToken(keyPair2, "a2a", Instant.now().plusSeconds(3_600L), Instant.now().plusSeconds(3_600_000L), "jwtId");
 
 
 		when(a2AClientLegacyPropConfig.getPublicKeysAsMap()).thenReturn(Map.of("A2A-IPA_TEST_1", publicKey));
@@ -93,8 +96,8 @@ void GivenInvalidIatThenInvalidTokenException() {
 
 	@Test
 	void GivenInvalidExpThenInvalidTokenException() {
-		PublicKey publicKey = keyPair.getPublic();
-		String token = JWTValidatorUtils.generateLegacyToken(keyPair, "a2a", Instant.now(), Instant.now().minusSeconds(3_600L), "jwtId");
+		PublicKey publicKey = keyPair2.getPublic();
+		String token = JWTValidatorUtils.generateLegacyToken(keyPair2, "a2a", Instant.now(), Instant.now().minusSeconds(3_600L), "jwtId");
 
 		when(a2AClientLegacyPropConfig.getPublicKeysAsMap()).thenReturn(Map.of("A2A-IPA_TEST_1", publicKey));
 
@@ -106,8 +109,8 @@ void GivenInvalidExpThenInvalidTokenException() {
 
 	@Test
 	void GivenInvalidJtiThenInvalidTokenException() {
-		PublicKey publicKey = keyPair.getPublic();
-		String token = JWTValidatorUtils.generateLegacyToken(keyPair, "a2a", Instant.now(), Instant.now().plusSeconds(3_600L), "");
+		PublicKey publicKey = keyPair2.getPublic();
+		String token = JWTValidatorUtils.generateLegacyToken(keyPair2, "a2a", Instant.now(), Instant.now().plusSeconds(3_600L), "");
 
 		when(a2AClientLegacyPropConfig.getPublicKeysAsMap()).thenReturn(Map.of("A2A-IPA_TEST_1", publicKey));