privacy-ethereum · 0xmad · Apr 9, 2026
diff --git a/gas-benchmarks/src/fluidkey/index.ts b/gas-benchmarks/src/fluidkey/index.ts
@@ -1,6 +1,7 @@
 import { mainnet } from "viem/chains";
 
-import type { FeeMetrics } from "../utils/types.js";
+import type { IAggregatedMetrics } from "./types.js";
+import type { TransactionReceipt } from "viem";
 
 import { BLOCK_WINDOW_ETHEREUM_5_WEEKS, BLOCK_WINDOW_ETHEREUM_10_MINUTES, MIN_SAMPLES } from "../utils/constants.js";
 import { getValidEthTransfers, getValidTransactions } from "../utils/rpc.js";
@@ -20,18 +21,27 @@ export class Fluidkey {
 
   readonly version = FLUIDKEY_CONFIG.version;
 
-  async benchmark(): Promise<Record<string, FeeMetrics>> {
-    const [shieldEth, shieldErc20, transferEth, transferErc20] = await Promise.all([
+  async benchmark(): Promise<IAggregatedMetrics> {
+    const [shieldEthReceipts, shieldErc20Receipts, transferEthReceipts, transferErc20Receipts] = await Promise.all([
       this.benchmarkShieldETH(),
       this.benchmarkShieldERC20(),
       this.benchmarkTransferETH(),
       this.benchmarkTransferERC20(),
     ]);
 
-    return { shieldEth, shieldErc20, transferEth, transferErc20 };
+    return {
+      shieldEth: getAverageMetrics(shieldEthReceipts),
+      shieldErc20: getAverageMetrics(shieldErc20Receipts),
+      transferEth: getAverageMetrics(transferEthReceipts),
+      transferErc20: getAverageMetrics(transferErc20Receipts),
+      anonymitySetSize: {
+        eth: shieldEthReceipts.length - transferEthReceipts.length,
+        ...this.benchmarkAnonymitySetSizeERC20(shieldErc20Receipts, transferErc20Receipts),
+      },
+    };
   }
 
-  async benchmarkShieldETH(): Promise<FeeMetrics> {
+  private async benchmarkShieldETH(): Promise<TransactionReceipt[]> {
     const receipts = await getValidEthTransfers({
       chain: mainnet,
       blockWindow: BLOCK_WINDOW_ETHEREUM_10_MINUTES, // TODO: fetch native ETH txs using block window
@@ -41,10 +51,10 @@ export class Fluidkey {
       throw new Error(`${this.name} shield ETH: receipts (${receipts.length}) < MIN_SAMPLES (${MIN_SAMPLES})`);
     }
 
-    return getAverageMetrics(receipts);
+    return receipts;
   }
 
-  async benchmarkShieldERC20(): Promise<FeeMetrics> {
+  private async benchmarkShieldERC20(): Promise<TransactionReceipt[]> {
     const receipts = await getValidTransactions({
       contractAddress: USDC_ERC20_TOKEN_ADDRESS,
       events: SHIELD_ERC20_EVENTS,
@@ -56,10 +66,10 @@ export class Fluidkey {
       throw new Error(`${this.name} shield ERC20: receipts (${receipts.length}) < MIN_SAMPLES (${MIN_SAMPLES})`);
     }
 
-    return getAverageMetrics(receipts);
+    return receipts;
   }
 
-  async benchmarkTransferETH(): Promise<FeeMetrics> {
+  private async benchmarkTransferETH(): Promise<TransactionReceipt[]> {
     const receipts = await getValidTransactions({
       contractAddress: FLUIDKEY_RELAYER_CONTRACT,
       events: TRANSFER_ETH_EVENTS,
@@ -71,10 +81,10 @@ export class Fluidkey {
       throw new Error(`${this.name} transfer ETH: receipts (${receipts.length}) < MIN_SAMPLES (${MIN_SAMPLES})`);
     }
 
-    return getAverageMetrics(receipts);
+    return receipts;
   }
 
-  async benchmarkTransferERC20(): Promise<FeeMetrics> {
+  private async benchmarkTransferERC20(): Promise<TransactionReceipt[]> {
     const receipts = await getValidTransactions({
       contractAddress: FLUIDKEY_RELAYER_CONTRACT,
       events: TRANSFER_ERC20_EVENTS,
@@ -85,6 +95,39 @@ export class Fluidkey {
       throw new Error(`${this.name} transfer ERC20: receipts (${receipts.length}) < MIN_SAMPLES (${MIN_SAMPLES})`);
     }
 
-    return getAverageMetrics(receipts);
+    return receipts;
+  }
+
+  private benchmarkAnonymitySetSizeERC20(
+    shieldReceipts: TransactionReceipt[],
+    transferReceipts: TransactionReceipt[],
+  ): Record<string, bigint | number> {
+    const shieldMap = shieldReceipts.reduce((map, receipt) => {
+      const address = receipt.to;
+
+      if (address) {
+        const count = map.get(address) ?? 0;
+        map.set(address, count + 1);
+      }
+
+      return map;
+    }, new Map<string, number>());
+
+    const unshieldMap = transferReceipts.reduce((map, receipt) => {
+      const address = receipt.to;
+
+      if (address) {
+        const count = map.get(address) ?? 0;
+        map.set(address, count + 1);
+      }
+
+      return map;
+    }, new Map<string, number>());
+
+    return [...shieldMap.entries()].reduce<Record<string, bigint | number>>((acc, [address, count]) => {
+      acc[address] = count - (unshieldMap.get(address) ?? 0);
+
+      return acc;
+    }, {});
   }
 }
diff --git a/gas-benchmarks/src/fluidkey/types.ts b/gas-benchmarks/src/fluidkey/types.ts
@@ -0,0 +1,31 @@
+import type { FeeMetrics } from "../utils/types.js";
+
+/**
+ * Interface representing the aggregated metrics
+ */
+export interface IAggregatedMetrics {
+  /**
+   * The average fee metrics for the shield ETH operation, including average gas used, average gas price, and average transaction fee.
+   */
+  shieldEth: FeeMetrics;
+
+  /**
+   * The average fee metrics for the shield ERC20 operation, including average gas used, average gas price, and average transaction fee.
+   */
+  shieldErc20: FeeMetrics;
+
+  /**
+   * The average fee metrics for the transfer ETH operation, including average gas used, average gas price, and average transaction fee.
+   */
+  transferEth: FeeMetrics;
+
+  /**
+   * The average fee metrics for the transfer ERC20 operation, including average gas used, average gas price, and average transaction fee.
+   */
+  transferErc20: FeeMetrics;
+
+  /**
+   * The size of the anonymity set by native and ERC20 tokens, which represents the number of transactions that are indistinguishable from each other in terms of privacy.
+   */
+  anonymitySetSize: Record<string, bigint | number>;
+}
diff --git a/gas-benchmarks/src/hinkal/index.ts b/gas-benchmarks/src/hinkal/index.ts
@@ -1,6 +1,7 @@
 import { mainnet } from "viem/chains";
 
-import type { FeeMetrics } from "../utils/types.js";
+import type { IAggregatedMetrics } from "./types.js";
+import type { TransactionReceipt } from "viem";
 
 import { BLOCK_WINDOW_ETHEREUM_5_WEEKS, MIN_SAMPLES } from "../utils/constants.js";
 import { getValidTransactions } from "../utils/rpc.js";
@@ -21,19 +22,35 @@ export class Hinkal {
 
   readonly version = HINKAL_CONFIG.version;
 
-  async benchmark(): Promise<Record<string, FeeMetrics>> {
-    const [shieldEth, unshieldEth, internalTransfer, shieldErc20, unshieldErc20] = await Promise.all([
+  async benchmark(): Promise<IAggregatedMetrics> {
+    const [
+      shieldEthReceipts,
+      unshieldEthReceipts,
+      internalTransferReceipts,
+      shieldErc20Receipts,
+      unshieldErc20Receipts,
+    ] = await Promise.all([
       this.benchmarkShieldETH(),
       this.benchmarkUnshieldETH(),
       this.benchmarkInternalTransfer(),
       this.benchmarkShieldERC20(),
       this.benchmarkUnshieldERC20(),
     ]);
 
-    return { shieldEth, unshieldEth, internalTransfer, shieldErc20, unshieldErc20 };
+    return {
+      shieldEth: getAverageMetrics(shieldEthReceipts),
+      unshieldEth: getAverageMetrics(unshieldEthReceipts),
+      internalTransfer: getAverageMetrics(internalTransferReceipts),
+      shieldErc20: getAverageMetrics(shieldErc20Receipts),
+      unshieldErc20: getAverageMetrics(unshieldErc20Receipts),
+      anonymitySetSize: {
+        eth: shieldEthReceipts.length - unshieldEthReceipts.length,
+        ...this.benchmarkAnonymitySetSizeERC20(shieldErc20Receipts, unshieldErc20Receipts),
+      },
+    };
   }
 
-  async benchmarkShieldETH(): Promise<FeeMetrics> {
+  private async benchmarkShieldETH(): Promise<TransactionReceipt[]> {
     const receipts = await getValidTransactions({
       contractAddress: HINKAL_POOL,
       events: SHIELD_ETH_EVENTS,
@@ -45,10 +62,10 @@ export class Hinkal {
       throw new Error(`${this.name} shield ETH: receipts (${receipts.length}) < MIN_SAMPLES (${MIN_SAMPLES})`);
     }
 
-    return getAverageMetrics(receipts);
+    return receipts;
   }
 
-  async benchmarkUnshieldETH(): Promise<FeeMetrics> {
+  private async benchmarkUnshieldETH(): Promise<TransactionReceipt[]> {
     const receipts = await getValidTransactions({
       contractAddress: HINKAL_POOL,
       events: UNSHIELD_ETH_EVENTS,
@@ -60,10 +77,10 @@ export class Hinkal {
       throw new Error(`${this.name} unshield ETH: receipts (${receipts.length}) < MIN_SAMPLES (${MIN_SAMPLES})`);
     }
 
-    return getAverageMetrics(receipts);
+    return receipts;
   }
 
-  async benchmarkInternalTransfer(): Promise<FeeMetrics> {
+  private async benchmarkInternalTransfer(): Promise<TransactionReceipt[]> {
     const receipts = await getValidTransactions({
       contractAddress: HINKAL_POOL,
       events: INTERNAL_TRANSFER_EVENTS,
@@ -75,10 +92,10 @@ export class Hinkal {
       throw new Error(`${this.name} internal transfer: receipts (${receipts.length}) < MIN_SAMPLES (${MIN_SAMPLES})`);
     }
 
-    return getAverageMetrics(receipts);
+    return receipts;
   }
 
-  async benchmarkShieldERC20(): Promise<FeeMetrics> {
+  private async benchmarkShieldERC20(): Promise<TransactionReceipt[]> {
     const receipts = await getValidTransactions({
       contractAddress: HINKAL_POOL,
       events: SHIELD_ERC20_EVENTS,
@@ -90,10 +107,10 @@ export class Hinkal {
       throw new Error(`${this.name} shield ERC20: receipts (${receipts.length}) < MIN_SAMPLES (${MIN_SAMPLES})`);
     }
 
-    return getAverageMetrics(receipts);
+    return receipts;
   }
 
-  async benchmarkUnshieldERC20(): Promise<FeeMetrics> {
+  private async benchmarkUnshieldERC20(): Promise<TransactionReceipt[]> {
     const receipts = await getValidTransactions({
       contractAddress: HINKAL_POOL,
       events: UNSHIELD_ERC20_EVENTS,
@@ -105,6 +122,39 @@ export class Hinkal {
       throw new Error(`${this.name} unshield ERC20: receipts (${receipts.length}) < MIN_SAMPLES (${MIN_SAMPLES})`);
     }
 
-    return getAverageMetrics(receipts);
+    return receipts;
+  }
+
+  private benchmarkAnonymitySetSizeERC20(
+    shieldReceipts: TransactionReceipt[],
+    unshieldReceipts: TransactionReceipt[],
+  ): Record<string, bigint | number> {
+    const shieldMap = shieldReceipts.reduce((map, receipt) => {
+      const address = receipt.to;
+
+      if (address) {
+        const count = map.get(address) ?? 0;
+        map.set(address, count + 1);
+      }
+
+      return map;
+    }, new Map<string, number>());
+
+    const unshieldMap = unshieldReceipts.reduce((map, receipt) => {
+      const address = receipt.to;
+
+      if (address) {
+        const count = map.get(address) ?? 0;
+        map.set(address, count + 1);
+      }
+
+      return map;
+    }, new Map<string, number>());
+
+    return [...shieldMap.entries()].reduce<Record<string, bigint | number>>((acc, [address, count]) => {
+      acc[address] = count - (unshieldMap.get(address) ?? 0);
+
+      return acc;
+    }, {});
   }
 }
diff --git a/gas-benchmarks/src/hinkal/types.ts b/gas-benchmarks/src/hinkal/types.ts
@@ -0,0 +1,36 @@
+import type { FeeMetrics } from "../utils/types.js";
+
+/**
+ * Interface representing the aggregated metrics
+ */
+export interface IAggregatedMetrics {
+  /**
+   * The average fee metrics for the shield ERC20 operation, including average gas used, average gas price, and average transaction fee.
+   */
+  shieldErc20: FeeMetrics;
+
+  /**
+   * The average fee metrics for the unshield ERC20 operation, including average gas used, average gas price, and average transaction fee.
+   */
+  unshieldErc20: FeeMetrics;
+
+  /**
+   * The average fee metrics for the internal transfers operation, including average gas used, average gas price, and average transaction fee.
+   */
+  internalTransfer: FeeMetrics;
+
+  /**
+   * The average fee metrics for the shield ETH operation, including average gas used, average gas price, and average transaction fee.
+   */
+  shieldEth: FeeMetrics;
+
+  /**
+   * The average fee metrics for the unshield ETH operation, including average gas used, average gas price, and average transaction fee.
+   */
+  unshieldEth: FeeMetrics;
+
+  /**
+   * The size of the anonymity set by native and ERC20 tokens, which represents the number of transactions that are indistinguishable from each other in terms of privacy.
+   */
+  anonymitySetSize: Record<string, bigint | number>;
+}
diff --git a/gas-benchmarks/src/index.ts b/gas-benchmarks/src/index.ts
@@ -43,29 +43,34 @@ await db.update((data) => {
     shield_erc20: railgunMetrics.shieldErc20,
     unshield_erc20: railgunMetrics.unshieldErc20,
     transfer_erc20: railgunMetrics.transferErc20,
+    anonymity_set_size: railgunMetrics.anonymitySetSize,
   };
 
   // eslint-disable-next-line no-param-reassign
   data[`${tornadoCash.name}_${tornadoCash.version}`] = {
     shield_eth: tornadoCashMetrics.shieldEth,
     unshield_eth: tornadoCashMetrics.unshieldEth,
+    anonymity_set_size: tornadoCashMetrics.anonymitySetSize,
   };
 
   // eslint-disable-next-line no-param-reassign
   data[`${privacyPools.name}_${privacyPools.version}`] = {
     shield_eth: privacyPoolsMetrics.shieldEth,
     unshield_eth: privacyPoolsMetrics.unshieldEth,
+    anonymity_set_size: privacyPoolsMetrics.anonymitySetSize,
   };
 
   // eslint-disable-next-line no-param-reassign
   data[`${intmax.name}_${intmax.version}`] = {
     deposit_eth: intmaxMetrics.depositEth,
     withdraw_eth: intmaxMetrics.withdrawEth,
+    anonymity_set_size: intmaxMetrics.anonymitySetSize,
   };
 
   // eslint-disable-next-line no-param-reassign
   data[`${monero.name}_${monero.version}`] = {
     transfer: moneroMetrics.transfer,
+    anonymity_set_size: moneroMetrics.anonymitySetSize,
   };
 
   // eslint-disable-next-line no-param-reassign
@@ -76,6 +81,7 @@ await db.update((data) => {
     shield_erc20: hinkalMetrics.shieldErc20,
     unshield_erc20: hinkalMetrics.unshieldErc20,
     transfer_erc20: hinkalMetrics.internalTransfer,
+    anonymity_set_size: hinkalMetrics.anonymitySetSize,
   };
 
   // eslint-disable-next-line no-param-reassign
@@ -84,6 +90,7 @@ await db.update((data) => {
     shield_erc20: fluidkeyMetrics.shieldErc20,
     transfer_eth: fluidkeyMetrics.transferEth,
     transfer_erc20: fluidkeyMetrics.transferErc20,
+    anonymity_set_size: fluidkeyMetrics.anonymitySetSize,
   };
 });