diff --git a/apps/subgraph/src/maci.ts b/apps/subgraph/src/maci.ts
index ca2473c783..f6ad7128a2 100644
--- a/apps/subgraph/src/maci.ts
+++ b/apps/subgraph/src/maci.ts
@@ -51,7 +51,7 @@ export function handleDeployPoll(event: DeployPollEvent): void {
 
 export function handleSignUp(event: SignUpEvent): void {
   const user = createOrLoadUser(event.params._userPubKeyX, event.params._userPubKeyY, event);
-  createOrLoadAccount(event.params._stateIndex, event, user.id, event.params._voiceCreditBalance);
+  createOrLoadAccount(event.params._stateIndex, event, user.id);
 
   const maci = createOrLoadMACI(event);
   maci.numSignUps = maci.numSignUps.plus(ONE_BIG_INT);
diff --git a/apps/subgraph/templates/subgraph.template.yaml b/apps/subgraph/templates/subgraph.template.yaml
index 76b6ac291c..1ea3e50d2a 100644
--- a/apps/subgraph/templates/subgraph.template.yaml
+++ b/apps/subgraph/templates/subgraph.template.yaml
@@ -31,7 +31,7 @@ dataSources:
       eventHandlers:
         - event: DeployPoll(uint256,indexed uint256,indexed uint256,uint8)
           handler: handleDeployPoll
-        - event: SignUp(uint256,indexed uint256,indexed uint256,uint256,uint256,uint256)
+        - event: SignUp(uint256,uint256,indexed uint256,indexed uint256)
           handler: handleSignUp
       file: ./src/maci.ts
 templates:
diff --git a/packages/circuits/circom/anon/pollJoining.circom b/packages/circuits/circom/anon/pollJoining.circom
index b66513bac0..581cf0bfd1 100644
--- a/packages/circuits/circom/anon/pollJoining.circom
+++ b/packages/circuits/circom/anon/pollJoining.circom
@@ -1,64 +1,44 @@
 pragma circom 2.0.0;
 
-// circomlib import
-include "./mux1.circom";
-// zk-kit imports
-include "./safe-comparators.circom";
 // local imports
 include "../utils/hashers.circom";
 include "../utils/privToPubKey.circom";
 include "../trees/incrementalMerkleTree.circom";
 
 template PollJoining(stateTreeDepth) {
-    // Constants defining the structure and size of state.
-    var STATE_LEAF_LENGTH = 4;
+    // Constants defining the tree structure
     var STATE_TREE_ARITY = 2;
 
-    // Public key IDs.
-    var STATE_LEAF_PUB_X_IDX = 0;
-    var STATE_LEAF_PUB_Y_IDX = 1;
-    // Voice Credit balance id
-    var STATE_LEAF_VOICE_CREDIT_BALANCE_IDX = 2;
-    var N_BITS = 252;
-
     // User's private key
     signal input privKey;
     // Poll's private key
     signal input pollPrivKey;
     // Poll's public key
     signal input pollPubKey[2];
-    // The state leaf and related path elements.
-    signal input stateLeaf[STATE_LEAF_LENGTH];
     // Siblings
     signal input siblings[stateTreeDepth][STATE_TREE_ARITY - 1];
     // Indices
     signal input indices[stateTreeDepth];
     // User's hashed private key
     signal input nullifier;
-    // User's credits for poll joining (might be <= oldCredits)
-    signal input credits;
     // MACI State tree root which proves the user is signed up
     signal input stateRoot;
     // The actual tree depth (might be <= stateTreeDepth) Used in BinaryMerkleRoot
     signal input actualStateTreeDepth;
 
-    var computedNullifier = PoseidonHasher(1)([privKey]);
-    nullifier === computedNullifier;
-
     // User private to public key
     var derivedPubKey[2] = PrivToPubKey()(privKey);
-    derivedPubKey[0] === stateLeaf[STATE_LEAF_PUB_X_IDX];
-    derivedPubKey[1] === stateLeaf[STATE_LEAF_PUB_Y_IDX];
-    
-    // Poll private to public key
+    // Hash the public key
+    var pubKeyHash = PoseidonHasher(2)([derivedPubKey[0], derivedPubKey[1]]);
+
+    // Poll private to public key to verify the correct one is used to join the poll (public input)
     var derivedPollPubKey[2] = PrivToPubKey()(pollPrivKey);
     derivedPollPubKey[0] === pollPubKey[0];
     derivedPollPubKey[1] === pollPubKey[1];
 
     // Inclusion proof  
-    var stateLeafHash = PoseidonHasher(4)(stateLeaf);
     var stateLeafQip = BinaryMerkleRoot(stateTreeDepth)(
-        stateLeafHash,
+        pubKeyHash,
         actualStateTreeDepth,
         indices,
         siblings
@@ -66,10 +46,6 @@ template PollJoining(stateTreeDepth) {
 
     stateLeafQip === stateRoot;
 
-    // Check credits
-    var isCreditsValid = SafeLessEqThan(N_BITS)([credits, stateLeaf[STATE_LEAF_VOICE_CREDIT_BALANCE_IDX]]);
-    isCreditsValid === 1;
-
     // Check nullifier
     var hashedPrivKey = PoseidonHasher(1)([privKey]);
     hashedPrivKey === nullifier;
diff --git a/packages/cli/ts/commands/deployPoll.ts b/packages/cli/ts/commands/deployPoll.ts
index b69fb1a631..864da53615 100644
--- a/packages/cli/ts/commands/deployPoll.ts
+++ b/packages/cli/ts/commands/deployPoll.ts
@@ -1,4 +1,4 @@
-import { MACI__factory as MACIFactory, EMode, deployFreeForAllSignUpGatekeeper } from "maci-contracts";
+import { MACI__factory as MACIFactory, EMode, deployFreeForAllSignUpGatekeeper, deployConstantInitialVoiceCreditProxy } from "maci-contracts";
 import { PubKey } from "maci-domainobjs";
 
 import {
@@ -11,6 +11,7 @@ import {
   logGreen,
   type DeployPollArgs,
   type PollContracts,
+  DEFAULT_INITIAL_VOICE_CREDITS,
 } from "../utils";
 
 /**
@@ -27,6 +28,7 @@ export const deployPoll = async ({
   maciAddress,
   vkRegistryAddress,
   gatekeeperAddress,
+  voiceCreditProxyAddress,
   signer,
   quiet = true,
   useQuadraticVoting = false,
@@ -57,11 +59,19 @@ export const deployPoll = async ({
   let signupGatekeeperContractAddress =
     gatekeeperAddress || (await readContractAddress(`SignUpGatekeeper-${pollId.toString()}`, network?.name));
 
+  
+
   if (!signupGatekeeperContractAddress) {
     const contract = await deployFreeForAllSignUpGatekeeper(signer, true);
     signupGatekeeperContractAddress = await contract.getAddress();
   }
 
+  let initialVoiceCreditProxyAddress = voiceCreditProxyAddress || (await readContractAddress("VoiceCreditProxy", network?.name));
+  if (!initialVoiceCreditProxyAddress) {
+    const contract = await deployConstantInitialVoiceCreditProxy(DEFAULT_INITIAL_VOICE_CREDITS, signer, true);
+    initialVoiceCreditProxyAddress = await contract.getAddress();
+  }
+
   // required arg -> poll duration
   if (pollDuration <= 0) {
     logError("Duration cannot be <= 0");
@@ -115,6 +125,7 @@ export const deployPoll = async ({
       vkRegistry,
       useQuadraticVoting ? EMode.QV : EMode.NON_QV,
       signupGatekeeperContractAddress,
+      initialVoiceCreditProxyAddress,
       { gasLimit: 10000000 },
     );
 
diff --git a/packages/cli/ts/commands/genProofs.ts b/packages/cli/ts/commands/genProofs.ts
index e302a10c63..8415577757 100644
--- a/packages/cli/ts/commands/genProofs.ts
+++ b/packages/cli/ts/commands/genProofs.ts
@@ -272,7 +272,7 @@ export const genProofs = async ({
   const tallyStartTime = Date.now();
 
   const { tallyBatchSize } = poll.batchSizes;
-  const numStateLeaves = poll.stateLeaves.length;
+  const numStateLeaves = poll.pubKeys.length;
   let totalTallyBatches = numStateLeaves <= tallyBatchSize ? 1 : Math.floor(numStateLeaves / tallyBatchSize);
   if (numStateLeaves > tallyBatchSize && numStateLeaves % tallyBatchSize > 0) {
     totalTallyBatches += 1;
diff --git a/packages/cli/ts/commands/joinPoll.ts b/packages/cli/ts/commands/joinPoll.ts
index a78b52a6dc..e0c7b203a7 100644
--- a/packages/cli/ts/commands/joinPoll.ts
+++ b/packages/cli/ts/commands/joinPoll.ts
@@ -4,53 +4,39 @@ import { formatProofForVerifierContract, genSignUpTree, IGenSignUpTree } from "m
 import { MACI__factory as MACIFactory, Poll__factory as PollFactory } from "maci-contracts/typechain-types";
 import { CircuitInputs, IJsonMaciState, MaciState, IPollJoiningCircuitInputs } from "maci-core";
 import { poseidon, stringifyBigInts } from "maci-crypto";
-import { IVkObjectParams, Keypair, PrivKey, PubKey, StateLeaf } from "maci-domainobjs";
+import { IVkObjectParams, Keypair, PrivKey, PubKey } from "maci-domainobjs";
 
 import fs from "fs";
 
 import type { IJoinPollArgs, IJoinedUserArgs, IParsePollJoinEventsArgs, IJoinPollData } from "../utils";
 
-import { contractExists, logError, logYellow, info, logGreen, success, BLOCKS_STEP, DEFAULT_SG_DATA } from "../utils";
+import { contractExists, logError, logYellow, info, logGreen, success, BLOCKS_STEP, DEFAULT_SG_DATA, DEFAULT_IVCP_DATA } from "../utils";
 import { banner } from "../utils/banner";
 
 /**
  * Get state index and credit balance
  * either from command line or
  * from maci state leaves or from sign up leaves
- * @param stateIndex State index from the command
- * @param newVoiceCreditBalance Credit balance from the command
- * @param stateLeaves State leaves from maci state or sign up tree
+ * @param pubKeys Public keys from maci state or sign up tree
  * @param userMaciPubKey Public key of the maci user
- * @returns State index and credit balance
+ * @param stateIndex State index from the command
+ * @returns State index
  */
-const getStateIndexAndCreditBalance = (
-  stateIndex: bigint | null,
-  newVoiceCreditBalance: bigint | null,
-  stateLeaves: StateLeaf[],
+const getStateIndex = (
+  pubKeys: PubKey[],
   userMaciPubKey: PubKey,
-): [bigint | null, bigint | null] => {
-  let loadedStateIndex = stateIndex;
-  let loadedCreditBalance = newVoiceCreditBalance;
-
+  stateIndex?: bigint,
+): bigint | undefined => {
   if (!stateIndex) {
-    const index = stateLeaves.findIndex((leaf) => leaf.pubKey.equals(userMaciPubKey));
+    const index = pubKeys.findIndex((key) => key.equals(userMaciPubKey));
     if (index > 0) {
-      loadedStateIndex = BigInt(index);
+      return BigInt(index);
     } else {
       logError("State leaf not found");
     }
   }
 
-  if (!newVoiceCreditBalance) {
-    const balance = stateLeaves[Number(loadedStateIndex!)].voiceCreditBalance;
-    if (balance) {
-      loadedCreditBalance = balance;
-    } else {
-      logError("Voice credit balance not found");
-    }
-  }
-
-  return [loadedStateIndex, loadedCreditBalance];
+  return stateIndex;
 };
 
 /**
@@ -98,7 +84,6 @@ const generateAndVerifyProof = async (
  * @param stateTreeDepth Maci state tree depth
  * @param maciPrivKey User's private key for signing up
  * @param stateLeafIndex Index where the user is stored in the state leaves
- * @param credits Credits for voting
  * @param pollPrivKey Poll's private key for the poll joining
  * @param pollPubKey Poll's public key for the poll joining
  * @returns stringified circuit inputs
@@ -108,20 +93,11 @@ const joiningCircuitInputs = (
   stateTreeDepth: bigint,
   maciPrivKey: PrivKey,
   stateLeafIndex: bigint,
-  credits: bigint,
   pollPrivKey: PrivKey,
   pollPubKey: PubKey,
 ): IPollJoiningCircuitInputs => {
   // Get the state leaf on the index position
-  const { signUpTree: stateTree, stateLeaves } = signUpData;
-  const stateLeaf = stateLeaves[Number(stateLeafIndex)];
-  const { pubKey, voiceCreditBalance, timestamp } = stateLeaf;
-  const [pubKeyX, pubKeyY] = pubKey.asArray();
-  const stateLeafArray = [pubKeyX, pubKeyY, voiceCreditBalance, timestamp];
-
-  if (credits > voiceCreditBalance) {
-    logError("Credits must be lower than signed up credits");
-  }
+  const { signUpTree: stateTree } = signUpData;
 
   // calculate the path elements for the state tree given the original state tree
   const { siblings, index } = stateTree.generateProof(Number(stateLeafIndex));
@@ -160,11 +136,9 @@ const joiningCircuitInputs = (
     privKey: maciPrivKey.asCircuitInputs(),
     pollPrivKey: pollPrivKey.asCircuitInputs(),
     pollPubKey: pollPubKey.asCircuitInputs(),
-    stateLeaf: stateLeafArray,
     siblings: siblingsArray,
     indices,
     nullifier,
-    credits,
     stateRoot,
     actualStateTreeDepth,
   };
@@ -182,7 +156,6 @@ export const joinPoll = async ({
   privateKey,
   pollPrivKey,
   stateIndex,
-  newVoiceCreditBalance,
   stateFile,
   pollId,
   signer,
@@ -196,6 +169,7 @@ export const joinPoll = async ({
   pollWitgen,
   pollWasm,
   sgDataArg,
+  ivcpDataArg,
   quiet = true,
 }: IJoinPollArgs): Promise<IJoinPollData> => {
   banner(quiet);
@@ -230,8 +204,7 @@ export const joinPoll = async ({
 
   const pollContract = PollFactory.connect(pollContracts.poll, signer);
 
-  let loadedStateIndex: bigint | null;
-  let loadedCreditBalance: bigint | null;
+  let loadedStateIndex: bigint | undefined;
   let maciState: MaciState | undefined;
   let signUpData: IGenSignUpTree | undefined;
   let currentStateRootIndex: number;
@@ -251,11 +224,10 @@ export const joinPoll = async ({
       throw new Error("User the given nullifier has already joined");
     }
 
-    [loadedStateIndex, loadedCreditBalance] = getStateIndexAndCreditBalance(
-      stateIndex,
-      newVoiceCreditBalance,
-      maciState!.stateLeaves,
+    loadedStateIndex = getStateIndex(
+      maciState!.pubKeys,
       userMaciPubKey,
+      stateIndex,
     );
 
     // check < 1 cause index zero is a blank state leaf
@@ -265,12 +237,11 @@ export const joinPoll = async ({
 
     currentStateRootIndex = poll.maciStateRef.numSignUps - 1;
 
-    poll.updatePoll(BigInt(maciState!.stateLeaves.length));
+    poll.updatePoll(BigInt(maciState!.pubKeys.length));
 
     circuitInputs = poll.joiningCircuitInputs({
       maciPrivKey: userMaciPrivKey,
       stateLeafIndex: loadedStateIndex!,
-      credits: loadedCreditBalance!,
       pollPrivKey: pollPrivKeyDeserialized,
       pollPubKey,
     }) as unknown as CircuitInputs;
@@ -305,11 +276,10 @@ export const joinPoll = async ({
 
     currentStateRootIndex = Number(numSignups) - 1;
 
-    [loadedStateIndex, loadedCreditBalance] = getStateIndexAndCreditBalance(
-      stateIndex,
-      newVoiceCreditBalance,
-      signUpData.stateLeaves,
+    loadedStateIndex = getStateIndex(
+      maciState!.pubKeys,
       userMaciPubKey,
+      stateIndex,
     );
 
     // check < 1 cause index zero is a blank state leaf
@@ -322,7 +292,6 @@ export const joinPoll = async ({
       stateTreeDepth,
       userMaciPrivKey,
       loadedStateIndex!,
-      loadedCreditBalance!,
       pollPrivKeyDeserialized,
       pollPubKey,
     ) as unknown as CircuitInputs;
@@ -334,6 +303,7 @@ export const joinPoll = async ({
   let receipt: ContractTransactionReceipt | null = null;
 
   const sgData = sgDataArg || DEFAULT_SG_DATA;
+  const ivcpData = ivcpDataArg || DEFAULT_IVCP_DATA;
 
   try {
     // generate the proof for this batch
@@ -351,10 +321,10 @@ export const joinPoll = async ({
     const tx = await pollContract.joinPoll(
       nullifier,
       pollPubKey.asContractParam(),
-      loadedCreditBalance!,
       currentStateRootIndex,
       proof,
       sgData,
+      ivcpData,
     );
     receipt = await tx.wait();
     logYellow(quiet, info(`Transaction hash: ${receipt!.hash}`));
diff --git a/packages/cli/ts/commands/signup.ts b/packages/cli/ts/commands/signup.ts
index f7e3aa1859..7d836e0fb4 100644
--- a/packages/cli/ts/commands/signup.ts
+++ b/packages/cli/ts/commands/signup.ts
@@ -26,7 +26,7 @@ import type {
 
 import { banner } from "../utils/banner";
 import { contractExists } from "../utils/contracts";
-import { DEFAULT_IVCP_DATA, DEFAULT_SG_DATA } from "../utils/defaults";
+import { DEFAULT_SG_DATA } from "../utils/defaults";
 import { GatekeeperTrait } from "../utils/interfaces";
 import { info, logError, logGreen, logYellow, success } from "../utils/theme";
 
@@ -39,7 +39,6 @@ export const signup = async ({
   maciPubKey,
   maciAddress,
   sgDataArg,
-  ivcpDataArg,
   signer,
   quiet = true,
 }: SignupArgs): Promise<ISignupData> => {
@@ -57,17 +56,12 @@ export const signup = async ({
   }
 
   const sgData = sgDataArg || DEFAULT_SG_DATA;
-  const ivcpData = ivcpDataArg || DEFAULT_IVCP_DATA;
 
   // we validate that the signup data and voice credit data is valid
   if (!isBytesLike(sgData)) {
     logError("invalid signup gateway data");
   }
 
-  if (!isBytesLike(ivcpData)) {
-    logError("invalid initial voice credit proxy data");
-  }
-
   const maciContract = MACIFactory.connect(maciAddress, signer);
 
   let stateIndex = "";
@@ -76,7 +70,7 @@ export const signup = async ({
 
   try {
     // sign up to the MACI contract
-    const tx = await maciContract.signUp(userMaciPubKey.asContractParam(), sgData, ivcpData);
+    const tx = await maciContract.signUp(userMaciPubKey.asContractParam(), sgData);
     receipt = await tx.wait();
 
     logYellow(quiet, info(`Transaction hash: ${tx.hash}`));
diff --git a/packages/cli/ts/index.ts b/packages/cli/ts/index.ts
index c40a5166e9..cf4cfa7ce3 100644
--- a/packages/cli/ts/index.ts
+++ b/packages/cli/ts/index.ts
@@ -218,6 +218,7 @@ program
   .option("-i, --state-index <stateIndex>", "the user's state index", BigInt)
   .requiredOption("-s, --sg-data <sgData>", "the signup gateway data")
   .requiredOption("-esk, --poll-priv-key <pollPrivKey>", "the user ephemeral private key for the poll")
+  .option("-i, --ivcp-data <ivcpData>", "the initial voice credit proxy data")
   .option(
     "-nv, --new-voice-credit-balance <newVoiceCreditBalance>",
     "the voice credit balance of the user for the poll",
@@ -251,8 +252,7 @@ program
         maciAddress,
         privateKey,
         pollPrivKey: cmdObj.pollPrivKey,
-        stateIndex: cmdObj.stateIndex || null,
-        newVoiceCreditBalance: cmdObj.newVoiceCreditBalance || null,
+        stateIndex: cmdObj.stateIndex || undefined,
         stateFile: cmdObj.stateFile,
         pollId: cmdObj.pollId,
         signer,
@@ -267,6 +267,7 @@ program
         rapidsnark: cmdObj.rapidsnark,
         pollWitgen: cmdObj.pollWitnessgen,
         sgDataArg: cmdObj.sgData,
+        ivcpDataArg: cmdObj.ivcpData,
       });
     } catch (error) {
       program.error((error as Error).message, { exitCode: 1 });
@@ -456,7 +457,6 @@ program
   .requiredOption("-p, --pubkey <maciPubKey>", "the MACI public key")
   .option("-x, --maci-address <maciAddress>", "the MACI contract address")
   .option("-s, --sg-data <sgData>", "the signup gateway data")
-  .option("-i, --ivcp-data <ivcpData>", "the initial voice credit proxy data")
   .option("-q, --quiet <quiet>", "whether to print values to the console", (value) => value === "true", false)
   .option("-r, --rpc-provider <provider>", "the rpc provider URL")
   .action(async (cmdObj) => {
@@ -470,7 +470,6 @@ program
         maciPubKey: cmdObj.pubkey,
         maciAddress,
         sgDataArg: cmdObj.sgData,
-        ivcpDataArg: cmdObj.ivcpData,
         quiet: cmdObj.quiet,
         signer,
       });
diff --git a/packages/cli/ts/utils/interfaces.ts b/packages/cli/ts/utils/interfaces.ts
index 68467b9f7a..16a70ebf5c 100644
--- a/packages/cli/ts/utils/interfaces.ts
+++ b/packages/cli/ts/utils/interfaces.ts
@@ -324,6 +324,11 @@ export interface DeployPollArgs {
    * The address of the gatekeeper contract
    */
   gatekeeperAddress?: string;
+
+  /**
+   * The address of the initial voice credit proxy contract
+   */
+  voiceCreditProxyAddress?: string;
 }
 
 /**
@@ -374,11 +379,6 @@ export interface IJoinPollArgs {
    */
   privateKey: string;
 
-  /**
-   * User's credit balance for voting within this poll
-   */
-  newVoiceCreditBalance: bigint | null;
-
   /**
    * The id of the poll
    */
@@ -387,7 +387,7 @@ export interface IJoinPollArgs {
   /**
    * The index of the state leaf
    */
-  stateIndex: bigint | null;
+  stateIndex: bigint | undefined;
 
   /**
    * Whether to log the output
@@ -458,6 +458,11 @@ export interface IJoinPollArgs {
    * The signup gatekeeper data
    */
   sgDataArg?: string;
+
+  /**
+   * The initial voice credit proxy data
+   */
+  ivcpDataArg?: string;
 }
 
 /**
@@ -945,11 +950,6 @@ export interface SignupArgs {
    */
   sgDataArg?: string;
 
-  /**
-   * The initial voice credit proxy data
-   */
-  ivcpDataArg?: string;
-
   /**
    * Whether to log the output
    */
diff --git a/packages/contracts/contracts/MACI.sol b/packages/contracts/contracts/MACI.sol
index 3575d6a7cf..00bf901b28 100644
--- a/packages/contracts/contracts/MACI.sol
+++ b/packages/contracts/contracts/MACI.sol
@@ -7,18 +7,18 @@ import { ITallyFactory } from "./interfaces/ITallyFactory.sol";
 import { IVerifier } from "./interfaces/IVerifier.sol";
 import { IVkRegistry } from "./interfaces/IVkRegistry.sol";
 import { ISignUpGatekeeper } from "./interfaces/ISignUpGatekeeper.sol";
-import { InitialVoiceCreditProxy } from "./initialVoiceCreditProxy/InitialVoiceCreditProxy.sol";
+import { IInitialVoiceCreditProxy } from "./interfaces/IInitialVoiceCreditProxy.sol";
 import { SignUpGatekeeper } from "./gatekeepers/SignUpGatekeeper.sol";
 import { IMACI } from "./interfaces/IMACI.sol";
 import { Params } from "./utilities/Params.sol";
-import { Utilities } from "./utilities/Utilities.sol";
 import { DomainObjs } from "./utilities/DomainObjs.sol";
 import { CurveBabyJubJub } from "./crypto/BabyJubJub.sol";
+import { Hasher } from "./crypto/Hasher.sol";
 import { InternalLeanIMT, LeanIMTData } from "./trees/LeanIMT.sol";
 
 /// @title MACI - Minimum Anti-Collusion Infrastructure Version 1
 /// @notice A contract which allows users to sign up, and deploy new polls
-contract MACI is IMACI, DomainObjs, Params, Utilities {
+contract MACI is IMACI, DomainObjs, Params, Hasher {
   /// @notice The state tree depth is fixed. As such it should be as large as feasible
   /// so that there can be as many users as possible.  i.e. 2 ** 23 = 8388608
   /// this should also match the parameter of the circom circuits.
@@ -31,9 +31,8 @@ contract MACI is IMACI, DomainObjs, Params, Utilities {
 
   uint8 internal constant STATE_TREE_ARITY = 2;
 
-  /// @notice The hash of a blank state leaf
-  uint256 internal constant BLANK_STATE_LEAF_HASH =
-    uint256(6769006970205099520508948723718471724660867171122235270773600567925038008762);
+  uint256 internal constant PAD_KEY_HASH =
+    6769006970205099520508948723718471724660867171122235270773600567925038008762;
 
   /// @notice The roots of the empty ballot trees
   uint256[5] public emptyBallotRoots;
@@ -53,18 +52,13 @@ contract MACI is IMACI, DomainObjs, Params, Utilities {
   /// @notice Factory contract that deploy a Tally contract
   ITallyFactory public immutable tallyFactory;
 
-  /// @notice The state tree. Represents a mapping between each user's public key
-  /// and their voice credit balance.
+  /// @notice The state tree. Stores users' public keys
   LeanIMTData public leanIMTData;
 
   /// @notice Address of the SignUpGatekeeper, a contract which determines whether a
   /// user may sign up to vote
   SignUpGatekeeper public immutable signUpGatekeeper;
 
-  /// @notice The contract which provides the values of the initial voice credit
-  /// balance per user
-  InitialVoiceCreditProxy public immutable initialVoiceCreditProxy;
-
   /// @notice The array of the state tree roots for each sign up
   /// For the N'th sign up, the state tree root will be stored at the index N
   uint256[] public stateRootsOnSignUp;
@@ -79,11 +73,9 @@ contract MACI is IMACI, DomainObjs, Params, Utilities {
   // Events
   event SignUp(
     uint256 _stateIndex,
-    uint256 indexed _userPubKeyX,
-    uint256 indexed _userPubKeyY,
-    uint256 _voiceCreditBalance,
     uint256 _timestamp,
-    uint256 _stateLeaf
+    uint256 indexed _userPubKeyX,
+    uint256 indexed _userPubKeyY
   );
   event DeployPoll(
     uint256 _pollId,
@@ -103,7 +95,6 @@ contract MACI is IMACI, DomainObjs, Params, Utilities {
   /// @param _messageProcessorFactory The MessageProcessorFactory contract
   /// @param _tallyFactory The TallyFactory contract
   /// @param _signUpGatekeeper The SignUpGatekeeper contract
-  /// @param _initialVoiceCreditProxy The InitialVoiceCreditProxy contract
   /// @param _stateTreeDepth The depth of the state tree
   /// @param _emptyBallotRoots The roots of the empty ballot trees
   constructor(
@@ -111,19 +102,17 @@ contract MACI is IMACI, DomainObjs, Params, Utilities {
     IMessageProcessorFactory _messageProcessorFactory,
     ITallyFactory _tallyFactory,
     SignUpGatekeeper _signUpGatekeeper,
-    InitialVoiceCreditProxy _initialVoiceCreditProxy,
     uint8 _stateTreeDepth,
     uint256[5] memory _emptyBallotRoots
   ) payable {
     // initialize and insert the blank leaf
-    InternalLeanIMT._insert(leanIMTData, BLANK_STATE_LEAF_HASH);
-    stateRootsOnSignUp.push(BLANK_STATE_LEAF_HASH);
+    InternalLeanIMT._insert(leanIMTData, PAD_KEY_HASH);
+    stateRootsOnSignUp.push(PAD_KEY_HASH);
 
     pollFactory = _pollFactory;
     messageProcessorFactory = _messageProcessorFactory;
     tallyFactory = _tallyFactory;
     signUpGatekeeper = _signUpGatekeeper;
-    initialVoiceCreditProxy = _initialVoiceCreditProxy;
     stateTreeDepth = _stateTreeDepth;
     maxSignups = uint256(STATE_TREE_ARITY) ** uint256(_stateTreeDepth);
     emptyBallotRoots = _emptyBallotRoots;
@@ -140,13 +129,9 @@ contract MACI is IMACI, DomainObjs, Params, Utilities {
   ///     register() function. For instance, the POAPGatekeeper or
   ///     SignUpTokenGatekeeper requires this value to be the ABI-encoded
   ///     token ID.
-  /// @param _initialVoiceCreditProxyData Data to pass to the
-  ///     InitialVoiceCreditProxy, which allows it to determine how many voice
-  ///     credits this user should have.
   function signUp(
     PubKey memory _pubKey,
-    bytes memory _signUpGatekeeperData,
-    bytes memory _initialVoiceCreditProxyData
+    bytes memory _signUpGatekeeperData
   ) public virtual {
     // ensure we do not have more signups than what the circuits support
     if (leanIMTData.size >= maxSignups) revert TooManySignups();
@@ -160,17 +145,14 @@ contract MACI is IMACI, DomainObjs, Params, Utilities {
     // throw if the user has already registered or if ineligible to do so.
     signUpGatekeeper.register(msg.sender, _signUpGatekeeperData);
 
-    // Get the user's voice credit balance.
-    uint256 voiceCreditBalance = initialVoiceCreditProxy.getVoiceCredits(msg.sender, _initialVoiceCreditProxyData);
-
-    // Create a state leaf and insert it into the tree.
-    uint256 stateLeaf = hashStateLeaf(StateLeaf(_pubKey, voiceCreditBalance, block.timestamp));
-    uint256 stateRoot = InternalLeanIMT._insert(leanIMTData, stateLeaf);
+    // Hash the public key and insert it into the tree.
+    uint256 pubKeyHash = hashLeftRight(_pubKey.x, _pubKey.y);
+    uint256 stateRoot = InternalLeanIMT._insert(leanIMTData, pubKeyHash);
 
     // Store the current state tree root in the array
     stateRootsOnSignUp.push(stateRoot);
 
-    emit SignUp(leanIMTData.size - 1, _pubKey.x, _pubKey.y, voiceCreditBalance, block.timestamp, stateLeaf);
+    emit SignUp(leanIMTData.size - 1, block.timestamp, _pubKey.x, _pubKey.y);
   }
 
   /// @notice Deploy a new Poll contract.
@@ -181,6 +163,8 @@ contract MACI is IMACI, DomainObjs, Params, Utilities {
   /// @param _verifier The Verifier Contract
   /// @param _vkRegistry The VkRegistry Contract
   /// @param _mode Voting mode
+  /// @param _gatekeeper The gatekeeper contract
+  /// @param _initialVoiceCreditProxy The initial voice credit proxy contract
   function deployPoll(
     uint256 _duration,
     TreeDepths memory _treeDepths,
@@ -189,7 +173,8 @@ contract MACI is IMACI, DomainObjs, Params, Utilities {
     address _verifier,
     address _vkRegistry,
     Mode _mode,
-    address _gatekeeper
+    address _gatekeeper,
+    address _initialVoiceCreditProxy
   ) public virtual {
     // cache the poll to a local variable so we can increment it
     uint256 pollId = nextPollId;
@@ -211,7 +196,8 @@ contract MACI is IMACI, DomainObjs, Params, Utilities {
       maci: IMACI(address(this)),
       verifier: IVerifier(_verifier),
       vkRegistry: IVkRegistry(_vkRegistry),
-      gatekeeper: ISignUpGatekeeper(_gatekeeper)
+      gatekeeper: ISignUpGatekeeper(_gatekeeper),
+      initialVoiceCreditProxy: IInitialVoiceCreditProxy(_initialVoiceCreditProxy)
     });
 
     address p = pollFactory.deploy(
diff --git a/packages/contracts/contracts/Poll.sol b/packages/contracts/contracts/Poll.sol
index 83a700f0cd..23882b0a89 100644
--- a/packages/contracts/contracts/Poll.sol
+++ b/packages/contracts/contracts/Poll.sol
@@ -271,17 +271,18 @@ contract Poll is Params, Utilities, SnarkCommon, IPoll {
   /// @notice Join the poll for voting
   /// @param _nullifier Hashed user's private key to check whether user has already voted
   /// @param _pubKey Poll user's public key
-  /// @param _newVoiceCreditBalance User's credit balance for voting within this poll
   /// @param _stateRootIndex Index of the MACI's stateRootOnSignUp when the user signed up
   /// @param _proof The zk-SNARK proof
+  /// @param _signUpGatekeeperData Data to pass to the SignUpGatekeeper
+  /// @param _initialVoiceCreditProxyData Data to pass to the InitialVoiceCreditProxy
   function joinPoll(
     uint256 _nullifier,
     PubKey calldata _pubKey,
-    uint256 _newVoiceCreditBalance,
     uint256 _stateRootIndex,
     uint256[8] calldata _proof,
-    bytes memory _signUpGatekeeperData
-  ) public virtual isWithinVotingDeadline {
+    bytes memory _signUpGatekeeperData,
+    bytes memory _initialVoiceCreditProxyData
+  ) external virtual isWithinVotingDeadline {
     // Whether the user has already joined
     if (pollNullifier[_nullifier]) {
       revert UserAlreadyJoined();
@@ -291,31 +292,32 @@ contract Poll is Params, Utilities, SnarkCommon, IPoll {
     pollNullifier[_nullifier] = true;
 
     // Verify user's proof
-    if (!verifyPollProof(_nullifier, _newVoiceCreditBalance, _stateRootIndex, _pubKey, _proof)) {
+    if (!verifyPollProof(_nullifier, _stateRootIndex, _pubKey, _proof)) {
       revert InvalidPollProof();
     }
 
     // Check if the user is eligible to join the poll
     extContracts.gatekeeper.register(msg.sender, _signUpGatekeeperData);
 
+    // Get the user's voice credit balance.
+    uint256 voiceCreditBalance = extContracts.initialVoiceCreditProxy.getVoiceCredits(msg.sender, _initialVoiceCreditProxyData);
+
     // Store user in the pollStateTree
-    uint256 stateLeaf = hashStateLeaf(StateLeaf(_pubKey, _newVoiceCreditBalance, block.timestamp));
+    uint256 stateLeaf = hashStateLeaf(StateLeaf(_pubKey, voiceCreditBalance, block.timestamp));
     InternalLazyIMT._insert(pollStateTree, stateLeaf);
 
     uint256 pollStateIndex = pollStateTree.numberOfLeaves - 1;
-    emit PollJoined(_pubKey.x, _pubKey.y, _newVoiceCreditBalance, block.timestamp, _nullifier, pollStateIndex);
+    emit PollJoined(_pubKey.x, _pubKey.y, voiceCreditBalance, block.timestamp, _nullifier, pollStateIndex);
   }
 
   /// @notice Verify the proof for Poll
   /// @param _nullifier Hashed user's private key to check whether user has already voted
-  /// @param _voiceCreditBalance User's credit balance for voting
   /// @param _index Index of the MACI's stateRootOnSignUp when the user signed up
   /// @param _pubKey Poll user's public key
   /// @param _proof The zk-SNARK proof
   /// @return isValid Whether the proof is valid
   function verifyPollProof(
     uint256 _nullifier,
-    uint256 _voiceCreditBalance,
     uint256 _index,
     PubKey calldata _pubKey,
     uint256[8] memory _proof
@@ -327,30 +329,27 @@ contract Poll is Params, Utilities, SnarkCommon, IPoll {
     );
 
     // Generate the circuit public input
-    uint256[] memory circuitPublicInputs = getPublicCircuitInputs(_nullifier, _voiceCreditBalance, _index, _pubKey);
+    uint256[] memory circuitPublicInputs = getPublicCircuitInputs(_nullifier, _index, _pubKey);
 
     isValid = extContracts.verifier.verify(_proof, vk, circuitPublicInputs);
   }
 
   /// @notice Get public circuit inputs for poll joining circuit
   /// @param _nullifier Hashed user's private key to check whether user has already voted
-  /// @param _voiceCreditBalance User's credit balance for voting
   /// @param _index Index of the MACI's stateRootOnSignUp when the user signed up
   /// @param _pubKey Poll user's public key
   /// @return publicInputs Public circuit inputs
   function getPublicCircuitInputs(
     uint256 _nullifier,
-    uint256 _voiceCreditBalance,
     uint256 _index,
     PubKey calldata _pubKey
   ) public view returns (uint256[] memory publicInputs) {
-    publicInputs = new uint256[](5);
+    publicInputs = new uint256[](4);
 
     publicInputs[0] = _pubKey.x;
     publicInputs[1] = _pubKey.y;
     publicInputs[2] = _nullifier;
-    publicInputs[3] = _voiceCreditBalance;
-    publicInputs[4] = extContracts.maci.getStateRootOnIndexedSignUp(_index);
+    publicInputs[3] = extContracts.maci.getStateRootOnIndexedSignUp(_index);
   }
 
   /// @inheritdoc IPoll
diff --git a/packages/contracts/contracts/interfaces/IInitialVoiceCreditProxy.sol b/packages/contracts/contracts/interfaces/IInitialVoiceCreditProxy.sol
new file mode 100644
index 0000000000..546e0e9b6f
--- /dev/null
+++ b/packages/contracts/contracts/interfaces/IInitialVoiceCreditProxy.sol
@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.10;
+
+/// @title IInitialVoiceCreditProxy
+/// @notice InitialVoiceCreditProxy interface
+interface IInitialVoiceCreditProxy {
+  /// @notice Get the voice credits of a user
+  /// @param _user User address
+  /// @param _data Data to get voice credits
+  function getVoiceCredits(address _user, bytes memory _data) external view returns (uint256);
+}
diff --git a/packages/contracts/contracts/interfaces/IPoll.sol b/packages/contracts/contracts/interfaces/IPoll.sol
index b17491e6ad..2deeb5e9c5 100644
--- a/packages/contracts/contracts/interfaces/IPoll.sol
+++ b/packages/contracts/contracts/interfaces/IPoll.sol
@@ -11,10 +11,10 @@ interface IPoll {
   function joinPoll(
     uint256 _nullifier,
     DomainObjs.PubKey calldata _pubKey,
-    uint256 _newVoiceCreditBalance,
     uint256 _stateRootIndex,
     uint256[8] calldata _proof,
-    bytes memory _signUpGatekeeperData
+    bytes memory _signUpGatekeeperData,
+    bytes memory _initialVoiceCreditProxyData
   ) external;
 
   /// @notice The number of messages which have been processed and the number of signups
diff --git a/packages/contracts/contracts/utilities/Params.sol b/packages/contracts/contracts/utilities/Params.sol
index 91d9fae8e0..87d0e10f7f 100644
--- a/packages/contracts/contracts/utilities/Params.sol
+++ b/packages/contracts/contracts/utilities/Params.sol
@@ -5,6 +5,7 @@ import { IMACI } from "../interfaces/IMACI.sol";
 import { IVerifier } from "../interfaces/IVerifier.sol";
 import { IVkRegistry } from "../interfaces/IVkRegistry.sol";
 import { ISignUpGatekeeper } from "../interfaces/ISignUpGatekeeper.sol";
+import { IInitialVoiceCreditProxy } from "../interfaces/IInitialVoiceCreditProxy.sol";
 
 /// @title Params
 /// @notice This contracts contains a number of structures
@@ -26,5 +27,6 @@ contract Params {
     IVerifier verifier;
     IVkRegistry vkRegistry;
     ISignUpGatekeeper gatekeeper;
+    IInitialVoiceCreditProxy  initialVoiceCreditProxy;
   }
 }
diff --git a/packages/contracts/tasks/deploy/maci/01-constantInitialVoiceCreditProxy.ts b/packages/contracts/tasks/deploy/poll/01-constantInitialVoiceCreditProxy.ts
similarity index 100%
rename from packages/contracts/tasks/deploy/maci/01-constantInitialVoiceCreditProxy.ts
rename to packages/contracts/tasks/deploy/poll/01-constantInitialVoiceCreditProxy.ts
diff --git a/packages/contracts/tasks/deploy/poll/01-gatekeepers.ts b/packages/contracts/tasks/deploy/poll/02-gatekeepers.ts
similarity index 100%
rename from packages/contracts/tasks/deploy/poll/01-gatekeepers.ts
rename to packages/contracts/tasks/deploy/poll/02-gatekeepers.ts
diff --git a/packages/contracts/tasks/deploy/poll/02-poll.ts b/packages/contracts/tasks/deploy/poll/03-poll.ts
similarity index 95%
rename from packages/contracts/tasks/deploy/poll/02-poll.ts
rename to packages/contracts/tasks/deploy/poll/03-poll.ts
index 98b48ee5b8..23b38b782b 100644
--- a/packages/contracts/tasks/deploy/poll/02-poll.ts
+++ b/packages/contracts/tasks/deploy/poll/03-poll.ts
@@ -53,6 +53,11 @@ deployment.deployTask(EDeploySteps.Poll, "Deploy poll").then((task) =>
       deployment.getDeployConfigField<EContracts | null>(EContracts.Poll, "gatekeeper") ||
       EContracts.FreeForAllGatekeeper;
     const gatekeeperContractAddress = storage.mustGetAddress(gatekeeper, hre.network.name, `poll-${pollId}`);
+    const initialVoiceCreditProxyContractAddress = storage.mustGetAddress(
+      EContracts.ConstantInitialVoiceCreditProxy,
+      hre.network.name,
+      `poll-${pollId}`,
+    );
 
     const tx = await maciContract.deployPoll(
       pollDuration,
@@ -66,6 +71,7 @@ deployment.deployTask(EDeploySteps.Poll, "Deploy poll").then((task) =>
       vkRegistryContractAddress,
       mode,
       gatekeeperContractAddress,
+      initialVoiceCreditProxyContractAddress,
     );
 
     const receipt = await tx.wait();
diff --git a/packages/contracts/tasks/helpers/ProofGenerator.ts b/packages/contracts/tasks/helpers/ProofGenerator.ts
index 7583a0c550..ac1bd3e313 100644
--- a/packages/contracts/tasks/helpers/ProofGenerator.ts
+++ b/packages/contracts/tasks/helpers/ProofGenerator.ts
@@ -252,7 +252,7 @@ export class ProofGenerator {
 
     console.log(`Generating proofs of vote tallying...`);
     const { tallyBatchSize } = this.poll.batchSizes;
-    const numStateLeaves = this.poll.stateLeaves.length;
+    const numStateLeaves = this.poll.pollStateLeaves.length;
     let totalTallyBatches = numStateLeaves <= tallyBatchSize ? 1 : Math.floor(numStateLeaves / tallyBatchSize);
     if (numStateLeaves > tallyBatchSize && numStateLeaves % tallyBatchSize > 0) {
       totalTallyBatches += 1;
diff --git a/packages/contracts/tasks/helpers/constants.ts b/packages/contracts/tasks/helpers/constants.ts
index f8bcfec6c2..e0bbbbeac7 100644
--- a/packages/contracts/tasks/helpers/constants.ts
+++ b/packages/contracts/tasks/helpers/constants.ts
@@ -2,7 +2,6 @@
  * Deploy steps
  */
 export enum EDeploySteps {
-  ConstantInitialVoiceCreditProxy = "full:deploy-constant-initial-voice-credit-proxy",
   Gatekeepers = "full:deploy-gatekeepers",
   Verifier = "full:deploy-verifier",
   Poseidon = "full:deploy-poseidon",
@@ -11,6 +10,7 @@ export enum EDeploySteps {
   TallyFactory = "full:deploy-tally-factory",
   Maci = "full:deploy-maci",
   VkRegistry = "full:deploy-vk-registry",
+  ConstantInitialVoiceCreditProxy = "poll:deploy-constant-initial-voice-credit-proxy",
   PollGatekeeper = "poll:deploy-gatekeeper",
   Poll = "poll:deploy-poll",
 }
diff --git a/packages/contracts/ts/genMaciState.ts b/packages/contracts/ts/genMaciState.ts
index 4a9e800105..44701d72d6 100644
--- a/packages/contracts/ts/genMaciState.ts
+++ b/packages/contracts/ts/genMaciState.ts
@@ -76,9 +76,7 @@ export const genMaciStateFromContract = async (
         data: {
           stateIndex: Number(event.args._stateIndex),
           pubKey: new PubKey([BigInt(event.args._userPubKeyX), BigInt(event.args._userPubKeyY)]),
-          voiceCreditBalance: Number(event.args._voiceCreditBalance),
           timestamp: Number(event.args._timestamp),
-          stateLeaf: BigInt(event.args._stateLeaf),
         },
       });
     });
@@ -196,9 +194,9 @@ export const genMaciStateFromContract = async (
   sortActions(actions).forEach((action) => {
     switch (true) {
       case action.type === "SignUp": {
-        const { pubKey, voiceCreditBalance, timestamp, stateLeaf } = action.data;
+        const { pubKey } = action.data;
 
-        maciState.signUp(pubKey!, BigInt(voiceCreditBalance!), BigInt(timestamp!), stateLeaf);
+        maciState.signUp(pubKey!);
         break;
       }
 
diff --git a/packages/contracts/ts/genSignUpTree.ts b/packages/contracts/ts/genSignUpTree.ts
index 598c47b795..c16b8241d2 100644
--- a/packages/contracts/ts/genSignUpTree.ts
+++ b/packages/contracts/ts/genSignUpTree.ts
@@ -1,7 +1,7 @@
 /* eslint-disable no-underscore-dangle */
 import { LeanIMT, LeanIMTHashFunction } from "@zk-kit/lean-imt";
-import { hashLeanIMT } from "maci-crypto";
-import { PubKey, StateLeaf, blankStateLeaf, blankStateLeafHash } from "maci-domainobjs";
+import { hashLeanIMT, hashLeftRight, PAD_KEY_HASH } from "maci-crypto";
+import { PubKey } from "maci-domainobjs";
 
 import { assert } from "console";
 
@@ -32,8 +32,8 @@ export const genSignUpTree = async ({
 
   const maciContract = MACIFactory.connect(address, provider);
   const signUpTree = new LeanIMT(hashLeanIMT as LeanIMTHashFunction);
-  signUpTree.insert(blankStateLeafHash);
-  const stateLeaves: StateLeaf[] = [blankStateLeaf];
+  signUpTree.insert(PAD_KEY_HASH);
+  const pubKeys: PubKey[] = [];
 
   // Fetch event logs in batches (lastBlock inclusive)
   for (let i = fromBlock; i <= lastBlock; i += blocksPerRequest + 1) {
@@ -47,14 +47,11 @@ export const genSignUpTree = async ({
       assert(!!event);
       const pubKeyX = event.args._userPubKeyX;
       const pubKeyY = event.args._userPubKeyY;
-      const voiceCreditBalance = event.args._voiceCreditBalance;
-      const timestamp = event.args._timestamp;
 
       const pubKey = new PubKey([pubKeyX, pubKeyY]);
-      const stateLeaf = new StateLeaf(pubKey, voiceCreditBalance, timestamp);
 
-      stateLeaves.push(stateLeaf);
-      signUpTree.insert(event.args._stateLeaf);
+      pubKeys.push(pubKey);
+      signUpTree.insert(hashLeftRight(pubKeyX, pubKeyY));
     });
 
     if (sleepAmount) {
@@ -64,6 +61,6 @@ export const genSignUpTree = async ({
   }
   return {
     signUpTree,
-    stateLeaves,
+    pubKeys,
   };
 };
diff --git a/packages/contracts/ts/types.ts b/packages/contracts/ts/types.ts
index 61435de2f3..24a82bc0dd 100644
--- a/packages/contracts/ts/types.ts
+++ b/packages/contracts/ts/types.ts
@@ -14,7 +14,7 @@ import type {
 } from "../typechain-types";
 import type { BigNumberish, Provider, Signer, ContractFactory } from "ethers";
 import type { CircuitInputs } from "maci-core";
-import type { Message, PubKey, StateLeaf } from "maci-domainobjs";
+import type { Message, PubKey } from "maci-domainobjs";
 import type { PublicSignals } from "snarkjs";
 
 /**
@@ -237,5 +237,5 @@ export interface IGenSignUpTree {
   /**
    * State leaves
    */
-  stateLeaves: StateLeaf[];
+  pubKeys: PubKey[];
 }
diff --git a/packages/core/ts/MaciState.ts b/packages/core/ts/MaciState.ts
index 506c51fbb1..c070dbba98 100644
--- a/packages/core/ts/MaciState.ts
+++ b/packages/core/ts/MaciState.ts
@@ -1,5 +1,5 @@
-import { hash4, IncrementalQuinTree } from "maci-crypto";
-import { type PubKey, type Keypair, StateLeaf, blankStateLeaf } from "maci-domainobjs";
+import { IncrementalQuinTree } from "maci-crypto";
+import { PubKey, type Keypair, padKey } from "maci-domainobjs";
 
 import type { IJsonMaciState, IJsonPoll, IMaciState, TreeDepths } from "./utils/types";
 
@@ -13,8 +13,8 @@ export class MaciState implements IMaciState {
   // a MaciState can hold multiple polls
   polls: Map<bigint, Poll> = new Map<bigint, Poll>();
 
-  // the leaves of the state tree
-  stateLeaves: StateLeaf[] = [];
+  // the public keys of the users
+  pubKeys: PubKey[] = [];
 
   // how deep the state tree is
   stateTreeDepth: number;
@@ -37,29 +37,22 @@ export class MaciState implements IMaciState {
     this.stateTreeDepth = stateTreeDepth;
 
     // we put a blank state leaf to prevent a DoS attack
-    this.stateLeaves.push(blankStateLeaf);
+    this.pubKeys.push(padKey);
     // we need to increase the number of signups by one given
     // that we already added the blank leaf
     this.numSignUps += 1;
   }
 
   /**
-   * Sign up a user with the given public key, initial voice credit balance, and timestamp.
+   * Sign up a user with the given public key.
    * @param pubKey - The public key of the user.
-   * @param initialVoiceCreditBalance - The initial voice credit balance of the user.
-   * @param timestamp - The timestamp of the sign-up.
-   * @param stateLeaf - The hash state leaf.
    * @returns The index of the newly signed-up user in the state tree.
    */
-  signUp(pubKey: PubKey, initialVoiceCreditBalance: bigint, timestamp: bigint, stateLeaf?: bigint): number {
+  signUp(pubKey: PubKey): number {
     this.numSignUps += 1;
-    const stateLeafObj = new StateLeaf(pubKey, initialVoiceCreditBalance, timestamp);
 
-    const pubKeyAsArray = pubKey.asArray();
-    const stateLeafHash =
-      stateLeaf || hash4([pubKeyAsArray[0], pubKeyAsArray[1], initialVoiceCreditBalance, timestamp]);
-    this.stateTree?.insert(stateLeafHash);
-    return this.stateLeaves.push(stateLeafObj.copy()) - 1;
+    this.stateTree?.insert(pubKey.hash());
+    return this.pubKeys.push(pubKey) - 1;
   }
 
   /**
@@ -105,7 +98,7 @@ export class MaciState implements IMaciState {
   copy = (): MaciState => {
     const copied = new MaciState(this.stateTreeDepth);
 
-    copied.stateLeaves = this.stateLeaves.map((x: StateLeaf) => x.copy());
+    copied.pubKeys = this.pubKeys.map((x: PubKey) => x.copy());
 
     copied.polls = new Map(Array.from(this.polls, ([key, value]) => [key, value.copy()]));
 
@@ -121,7 +114,7 @@ export class MaciState implements IMaciState {
     const result =
       this.stateTreeDepth === m.stateTreeDepth &&
       this.polls.size === m.polls.size &&
-      this.stateLeaves.length === m.stateLeaves.length;
+      this.pubKeys.length === m.pubKeys.length;
 
     if (!result) {
       return false;
@@ -132,8 +125,8 @@ export class MaciState implements IMaciState {
         return false;
       }
     }
-    for (let i = 0; i < this.stateLeaves.length; i += 1) {
-      if (!this.stateLeaves[i].equals(m.stateLeaves[i])) {
+    for (let i = 0; i < this.pubKeys.length; i += 1) {
+      if (!this.pubKeys[i].equals(m.pubKeys[i])) {
         return false;
       }
     }
@@ -149,7 +142,7 @@ export class MaciState implements IMaciState {
     return {
       stateTreeDepth: this.stateTreeDepth,
       polls: Array.from(this.polls.values()).map((poll) => poll.toJSON()),
-      stateLeaves: this.stateLeaves.map((leaf) => leaf.toJSON()),
+      pubKeys: this.pubKeys.map((pubKey) => pubKey.toJSON()),
       pollBeingProcessed: Boolean(this.pollBeingProcessed),
       currentPollBeingProcessed: this.currentPollBeingProcessed ? this.currentPollBeingProcessed.toString() : "",
       numSignUps: this.numSignUps,
@@ -165,7 +158,7 @@ export class MaciState implements IMaciState {
     const maciState = new MaciState(json.stateTreeDepth);
 
     // assign the json values to the new instance
-    maciState.stateLeaves = json.stateLeaves.map((leaf) => StateLeaf.fromJSON(leaf));
+    maciState.pubKeys = json.pubKeys.map((pubKey) => PubKey.fromJSON(pubKey));
     maciState.pollBeingProcessed = json.pollBeingProcessed;
     maciState.currentPollBeingProcessed = BigInt(json.currentPollBeingProcessed);
     maciState.numSignUps = json.numSignUps;
diff --git a/packages/core/ts/Poll.ts b/packages/core/ts/Poll.ts
index 1511410425..3c75bd6b2e 100644
--- a/packages/core/ts/Poll.ts
+++ b/packages/core/ts/Poll.ts
@@ -25,6 +25,7 @@ import {
   type IMessageContractParams,
   type IJsonPCommand,
   blankStateLeafHash,
+  padKey,
 } from "maci-domainobjs";
 
 import assert from "assert";
@@ -81,7 +82,7 @@ export class Poll implements IPoll {
 
   stateCopied = false;
 
-  stateLeaves: StateLeaf[] = [blankStateLeaf];
+  pubKeys: PubKey[] = [padKey];
 
   stateTree?: LeanIMT;
 
@@ -215,13 +216,13 @@ export class Poll implements IPoll {
     // start by setting the number of signups
     this.setNumSignups(numSignups);
     // copy up to numSignups state leaves
-    this.stateLeaves = this.maciStateRef.stateLeaves.slice(0, Number(this.numSignups)).map((x) => x.copy());
+    this.pubKeys = this.maciStateRef.pubKeys.slice(0, Number(this.numSignups)).map((x) => x.copy());
     // ensure we have the correct actual state tree depth value
     this.actualStateTreeDepth = Math.max(1, Math.ceil(Math.log2(Number(this.numSignups))));
 
     this.stateTree = new LeanIMT(hashLeanIMT as LeanIMTHashFunction);
     // add all leaves
-    this.stateLeaves.forEach((stateLeaf) => {
+    this.pubKeys.forEach((stateLeaf) => {
       this.stateTree?.insert(stateLeaf.hash());
     });
 
@@ -243,7 +244,7 @@ export class Poll implements IPoll {
     this.ballotTree.insert(this.emptyBallotHash);
 
     // we fill the ballotTree with empty ballots hashes to match the number of signups in the tree
-    while (this.ballots.length < this.stateLeaves.length) {
+    while (this.ballots.length < this.pubKeys.length) {
       this.ballotTree.insert(this.emptyBallotHash);
       this.ballots.push(this.emptyBallot);
     }
@@ -428,7 +429,6 @@ export class Poll implements IPoll {
    * Create circuit input for pollJoining
    * @param maciPrivKey User's private key for signing up
    * @param stateLeafIndex Index where the user is stored in the state leaves
-   * @param credits Credits for voting
    * @param pollPrivKey Poll's private key for the poll joining
    * @param pollPubKey Poll's public key for the poll joining
    * @returns stringified circuit inputs
@@ -436,19 +436,9 @@ export class Poll implements IPoll {
   joiningCircuitInputs = ({
     maciPrivKey,
     stateLeafIndex,
-    credits,
     pollPrivKey,
     pollPubKey,
-  }: IJoiningCircuitArgs): IPollJoiningCircuitInputs => {
-    // Get the state leaf on the index position
-    const stateLeaf = this.stateLeaves[Number(stateLeafIndex)];
-    const { pubKey, voiceCreditBalance, timestamp } = stateLeaf;
-    const pubKeyX = pubKey.asArray()[0];
-    const pubKeyY = pubKey.asArray()[1];
-    const stateLeafArray = [pubKeyX, pubKeyY, voiceCreditBalance, timestamp];
-
-    assert(credits <= voiceCreditBalance, "Credits must be lower than signed up credits");
-
+  }: IJoiningCircuitArgs): IPollJoiningCircuitInputs => {  
     // calculate the path elements for the state tree given the original state tree
     const { siblings, index } = this.stateTree!.generateProof(Number(stateLeafIndex));
     const siblingsLength = siblings.length;
@@ -483,11 +473,9 @@ export class Poll implements IPoll {
       privKey: maciPrivKey.asCircuitInputs(),
       pollPrivKey: pollPrivKey.asCircuitInputs(),
       pollPubKey: pollPubKey.asCircuitInputs(),
-      stateLeaf: stateLeafArray,
       siblings: siblingsArray,
       indices,
       nullifier,
-      credits,
       stateRoot,
       actualStateTreeDepth,
     };
@@ -1303,7 +1291,7 @@ export class Poll implements IPoll {
       this.maciStateRef,
     );
 
-    copied.stateLeaves = this.stateLeaves.map((x) => x.copy());
+    copied.pubKeys = this.pubKeys.map((x) => x.copy());
     copied.pollStateLeaves = this.pollStateLeaves.map((x) => x.copy());
     copied.messages = this.messages.map((x) => x.copy());
     copied.commands = this.commands.map((x) => x.copy());
@@ -1400,7 +1388,7 @@ export class Poll implements IPoll {
       ballots: this.ballots.map((ballot) => ballot.toJSON()),
       encPubKeys: this.encPubKeys.map((encPubKey) => encPubKey.serialize()),
       currentMessageBatchIndex: this.currentMessageBatchIndex,
-      stateLeaves: this.stateLeaves.map((leaf) => leaf.toJSON()),
+      pubKeys: this.pubKeys.map((leaf) => leaf.toJSON()),
       pollStateLeaves: this.pollStateLeaves.map((leaf) => leaf.toJSON()),
       results: this.tallyResult.map((result) => result.toString()),
       numBatchesProcessed: this.numBatchesProcessed,
diff --git a/packages/core/ts/utils/types.ts b/packages/core/ts/utils/types.ts
index d1b9a79708..d7f569f782 100644
--- a/packages/core/ts/utils/types.ts
+++ b/packages/core/ts/utils/types.ts
@@ -5,6 +5,7 @@ import type {
   Ballot,
   IJsonBallot,
   IJsonPCommand,
+  IJsonPublicKey,
   IJsonStateLeaf,
   Keypair,
   Message,
@@ -95,7 +96,7 @@ export interface IJsonPoll {
   ballots: IJsonBallot[];
   encPubKeys: string[];
   currentMessageBatchIndex: number;
-  stateLeaves: IJsonStateLeaf[];
+  pubKeys: IJsonPublicKey[];
   pollStateLeaves: IJsonStateLeaf[];
   results: string[];
   numBatchesProcessed: number;
@@ -110,7 +111,7 @@ export interface IJsonPoll {
 export interface IJsonMaciState {
   stateTreeDepth: number;
   polls: IJsonPoll[];
-  stateLeaves: IJsonStateLeaf[];
+  pubKeys: IJsonPublicKey[];
   pollBeingProcessed: boolean;
   currentPollBeingProcessed: string;
   numSignUps: number;
@@ -138,7 +139,6 @@ export interface IProcessMessagesOutput {
 export interface IJoiningCircuitArgs {
   maciPrivKey: PrivKey;
   stateLeafIndex: bigint;
-  credits: bigint;
   pollPrivKey: PrivKey;
   pollPubKey: PubKey;
 }
@@ -153,7 +153,6 @@ export interface IPollJoiningCircuitInputs {
   siblings: string[][];
   indices: string[];
   nullifier: string;
-  credits: string;
   stateRoot: string;
   actualStateTreeDepth: string;
 }
diff --git a/packages/crypto/ts/constants.ts b/packages/crypto/ts/constants.ts
index ce10528f2f..a0609ea14c 100644
--- a/packages/crypto/ts/constants.ts
+++ b/packages/crypto/ts/constants.ts
@@ -10,3 +10,5 @@ export const SNARK_FIELD_SIZE = r;
 export const NOTHING_UP_MY_SLEEVE = BigInt(keccak256(toUtf8Bytes("Maci"))) % SNARK_FIELD_SIZE;
 
 assert(NOTHING_UP_MY_SLEEVE === BigInt("8370432830353022751713833565135785980866757267633941821328460903436894336785"));
+
+export const PAD_KEY_HASH = BigInt("6769006970205099520508948723718471724660867171122235270773600567925038008762");
diff --git a/packages/crypto/ts/index.ts b/packages/crypto/ts/index.ts
index bfaf8e003c..5d95af0320 100644
--- a/packages/crypto/ts/index.ts
+++ b/packages/crypto/ts/index.ts
@@ -4,7 +4,7 @@ export { IncrementalQuinTree } from "./quinTree";
 
 export { bigInt2Buffer, stringifyBigInts, unstringifyBigInts, deepCopyBigIntArray } from "./bigIntUtils";
 
-export { NOTHING_UP_MY_SLEEVE, SNARK_FIELD_SIZE } from "./constants";
+export { NOTHING_UP_MY_SLEEVE, SNARK_FIELD_SIZE, PAD_KEY_HASH} from "./constants";
 
 export {
   genPrivKey,
diff --git a/packages/domainobjs/ts/constants.ts b/packages/domainobjs/ts/constants.ts
index aae4709cb1..bc727d7b03 100644
--- a/packages/domainobjs/ts/constants.ts
+++ b/packages/domainobjs/ts/constants.ts
@@ -1,4 +1,6 @@
+import { PubKey } from "./publicKey";
 import { StateLeaf } from "./stateLeaf";
 
 export const blankStateLeaf = StateLeaf.genBlankLeaf();
 export const blankStateLeafHash = blankStateLeaf.hash();
+export const padKey = PubKey.genPadKey();
diff --git a/packages/domainobjs/ts/index.ts b/packages/domainobjs/ts/index.ts
index ad8081b858..6aabb2e6dc 100644
--- a/packages/domainobjs/ts/index.ts
+++ b/packages/domainobjs/ts/index.ts
@@ -10,7 +10,7 @@ export { Keypair } from "./keyPair";
 
 export { StateLeaf } from "./stateLeaf";
 
-export { blankStateLeaf, blankStateLeafHash } from "./constants";
+export { blankStateLeaf, blankStateLeafHash, padKey } from "./constants";
 
 export type {
   Proof,
diff --git a/packages/domainobjs/ts/publicKey.ts b/packages/domainobjs/ts/publicKey.ts
index 905107975f..4f5e5f3958 100644
--- a/packages/domainobjs/ts/publicKey.ts
+++ b/packages/domainobjs/ts/publicKey.ts
@@ -135,4 +135,23 @@ export class PubKey {
   static fromJSON(json: IJsonPublicKey): PubKey {
     return PubKey.deserialize(json.pubKey);
   }
+
+  /**
+   * Generate a default pad key
+   * @returns a default pad key
+   */
+    static genPadKey(): PubKey {
+      // This public key is the first Pedersen base
+      // point from iden3's circomlib implementation of the Pedersen hash.
+      // Since it is generated using a hash-to-curve function, we are
+      // confident that no-one knows the private key associated with this
+      // public key. See:
+      // https://github.com/iden3/circomlib/blob/d5ed1c3ce4ca137a6b3ca48bec4ac12c1b38957a/src/pedersen_printbases.js
+      // Its hash should equal
+      // 6769006970205099520508948723718471724660867171122235270773600567925038008762.
+      return new PubKey([
+        BigInt("10457101036533406547632367118273992217979173478358440826365724437999023779287"),
+      BigInt("19824078218392094440610104313265183977899662750282163392862422243483260492317"),
+    ]);
+  }
 }
diff --git a/packages/integrationTests/ts/__tests__/integration.test.ts b/packages/integrationTests/ts/__tests__/integration.test.ts
index c3666f40f5..1f6d6050b3 100644
--- a/packages/integrationTests/ts/__tests__/integration.test.ts
+++ b/packages/integrationTests/ts/__tests__/integration.test.ts
@@ -34,7 +34,6 @@ import {
   VOTE_OPTION_TREE_DEPTH,
   duration,
   initialVoiceCredits,
-  ivcpData,
   maxMessages,
 } from "./utils/constants";
 import { ITestSuite } from "./utils/interfaces";
@@ -168,7 +167,6 @@ describe("Integration tests", function test() {
             maciPubKey: user.keypair.pubKey.serialize(),
             maciAddress: contracts.maciAddress,
             sgDataArg: SG_DATA,
-            ivcpDataArg: ivcpData,
             signer,
           }).then((result) => result.stateIndex),
         );
@@ -191,12 +189,11 @@ describe("Integration tests", function test() {
           ),
           rapidsnark: `${homedir()}/rapidsnark/build/prover`,
           signer,
-          newVoiceCreditBalance: BigInt(initialVoiceCredits),
           quiet: true,
         });
 
         // signup on local maci state
-        maciState.signUp(user.keypair.pubKey, BigInt(initialVoiceCredits), BigInt(timestamp));
+        maciState.signUp(user.keypair.pubKey);
 
         // join the poll on local
         const inputNullifier = BigInt(user.keypair.privKey.asCircuitInputs());
diff --git a/packages/integrationTests/ts/__tests__/maci-keys.test.ts b/packages/integrationTests/ts/__tests__/maci-keys.test.ts
index 081553e52f..97d59a8b97 100644
--- a/packages/integrationTests/ts/__tests__/maci-keys.test.ts
+++ b/packages/integrationTests/ts/__tests__/maci-keys.test.ts
@@ -72,7 +72,7 @@ describe("integration tests private/public/keypair", () => {
 
     before(async () => {
       signer = await getDefaultSigner();
-      const { maci, verifier, vkRegistry, gatekeeper } = await deployTestContracts(
+      const { maci, verifier, vkRegistry, gatekeeper, initialVoiceCreditProxy } = await deployTestContracts(
         initialVoiceCredits,
         STATE_TREE_DEPTH,
         signer,
@@ -92,6 +92,7 @@ describe("integration tests private/public/keypair", () => {
         vkRegistry,
         EMode.NON_QV,
         gatekeeper,
+        initialVoiceCreditProxy,
       );
 
       // we know it's the first poll so id is 0
diff --git a/packages/integrationTests/ts/__tests__/utils/interfaces.ts b/packages/integrationTests/ts/__tests__/utils/interfaces.ts
index 647a0b6ee5..abaf203580 100644
--- a/packages/integrationTests/ts/__tests__/utils/interfaces.ts
+++ b/packages/integrationTests/ts/__tests__/utils/interfaces.ts
@@ -1,4 +1,5 @@
 import { MACI, Verifier, VkRegistry, FreeForAllGatekeeper } from "maci-contracts";
+import { ConstantInitialVoiceCreditProxy } from "maci-contracts/typechain-types";
 
 /**
  * A util interface that represents a vote object
@@ -48,4 +49,5 @@ export interface IDeployedTestContracts {
   verifier: Verifier;
   vkRegistry: VkRegistry;
   gatekeeper: FreeForAllGatekeeper;
+  initialVoiceCreditProxy: ConstantInitialVoiceCreditProxy;
 }
diff --git a/packages/integrationTests/ts/__tests__/utils/utils.ts b/packages/integrationTests/ts/__tests__/utils/utils.ts
index 5b59cb923b..33d0d1f307 100644
--- a/packages/integrationTests/ts/__tests__/utils/utils.ts
+++ b/packages/integrationTests/ts/__tests__/utils/utils.ts
@@ -203,5 +203,6 @@ export const deployTestContracts = async (
     verifier: mockVerifierContract as Verifier,
     vkRegistry: vkRegistryContract,
     gatekeeper: gatekeeperContract,
+    initialVoiceCreditProxy: constantInitialVoiceCreditProxyContract,
   };
 };