diff --git a/modules/passkey-crypto/src/attachPasskeyToWallet.ts b/modules/passkey-crypto/src/attachPasskeyToWallet.ts
index 2771abccd1..f1c65ab4c4 100644
--- a/modules/passkey-crypto/src/attachPasskeyToWallet.ts
+++ b/modules/passkey-crypto/src/attachPasskeyToWallet.ts
@@ -67,7 +67,14 @@ export async function attachPasskeyToWallet(params: {
   }
 
   const prfPassword = derivePassword(authResult.prfResult);
-  const encryptedPrv = await bitgo.encrypt({ password: prfPassword, input: privateKey, encryptionVersion });
+  const encryptedPrv = await bitgo.encrypt({
+    password: prfPassword,
+    input: privateKey,
+    encryptionVersion,
+    // Bind to this enterprise via AES-GCM AAD — moving this blob to another enterprise
+    // or tampering with the stored adata field invalidates the GCM tag.
+    adata: enterpriseId,
+  });
 
   const updatedKeychain = await bitgo
     .put(bitgo.url(`/${coin}/key/${keychainId}`, 2))
diff --git a/modules/passkey-crypto/test/unit/attachPasskeyToWallet.test.ts b/modules/passkey-crypto/test/unit/attachPasskeyToWallet.test.ts
index 561746a142..a86ac7e784 100644
--- a/modules/passkey-crypto/test/unit/attachPasskeyToWallet.test.ts
+++ b/modules/passkey-crypto/test/unit/attachPasskeyToWallet.test.ts
@@ -153,9 +153,9 @@ describe('attachPasskeyToWallet', function () {
     assert.match(putBody.webauthnInfo.prfSalt, /^[A-Za-z0-9\-_]+$/);
     assert.strictEqual(typeof putBody.webauthnInfo.encryptedPrv, 'string');
 
-    // encrypt must be called with encryptionVersion 2
+    // encrypt must be called with encryptionVersion 2 and enterpriseId as AAD
     sinon.assert.calledOnce(mockBitGo.encrypt);
-    sinon.assert.calledWithMatch(mockBitGo.encrypt, { encryptionVersion: 2 });
+    sinon.assert.calledWithMatch(mockBitGo.encrypt, { encryptionVersion: 2, adata: enterpriseId });
 
     assert.strictEqual(result.id, keychainId);
   });
@@ -165,11 +165,12 @@ describe('attachPasskeyToWallet', function () {
 
     await callAttach();
 
-    // The PRF-derived password and the decrypted xprv must be passed to encrypt
+    // The PRF-derived password, decrypted xprv, and enterpriseId AAD must be passed to encrypt
     sinon.assert.calledWithMatch(mockBitGo.encrypt, {
       password: expectedPrfPassword,
       input: decryptedPrv,
       encryptionVersion: 2,
+      adata: enterpriseId,
     });
 
     // The v2 blob returned by encrypt is what gets stored on the server
diff --git a/modules/sdk-api/test/unit/encrypt.ts b/modules/sdk-api/test/unit/encrypt.ts
index 53d7dffb71..52eacaf608 100644
--- a/modules/sdk-api/test/unit/encrypt.ts
+++ b/modules/sdk-api/test/unit/encrypt.ts
@@ -191,6 +191,30 @@ describe('encryption methods tests', () => {
       await assert.rejects(() => decryptV2(password, JSON.stringify(envelope)), /operation-specific reason|incorrect/i);
     });
 
+    it('adata: undefined is equivalent to omitting adata', async () => {
+      const fixedOpts = {
+        memorySize: 1024,
+        iterations: 1,
+        parallelism: 1,
+        salt: new Uint8Array(16).fill(0xaa),
+        iv: new Uint8Array(12).fill(0xbb),
+      };
+      const withUndefined = await encryptV2(password, plaintext, { ...fixedOpts, adata: undefined });
+      const withOmitted = await encryptV2(password, plaintext, fixedOpts);
+      assert.strictEqual(withUndefined, withOmitted);
+      assert.strictEqual(await decryptV2(password, withUndefined), plaintext);
+    });
+
+    it('ciphertext bound to enterprise-A cannot be re-attributed to enterprise-B', async () => {
+      const prv = 'xprv-private-key-bytes';
+      const prfKey = 'prf-derived-key';
+      const ct = await encryptV2(prfKey, prv, { adata: 'enterprise-A' });
+      // Attacker moves blob to enterprise-B by altering the stored adata field
+      const envelope = JSON.parse(ct);
+      envelope.adata = 'enterprise-B';
+      await assert.rejects(() => decryptV2(prfKey, JSON.stringify(envelope)));
+    });
+
     it('v1 and v2 are independent (v1 data does not decrypt with v2)', async () => {
       const v1ct = await encrypt(password, plaintext, { encryptionVersion: 1 });
       await assert.rejects(() => decryptV2(password, v1ct), /invalid envelope/);
diff --git a/modules/sdk-core/src/bitgo/wallet/wallets.ts b/modules/sdk-core/src/bitgo/wallet/wallets.ts
index 76d3962cf6..9a27d73e7b 100644
--- a/modules/sdk-core/src/bitgo/wallet/wallets.ts
+++ b/modules/sdk-core/src/bitgo/wallet/wallets.ts
@@ -617,6 +617,7 @@ export class Wallets implements IWallets {
                 password: params.webauthnInfo.passphrase,
                 input: userKeychain.prv,
                 encryptionVersion: params.encryptionVersion,
+                adata: params.enterprise,
               }),
             };
           }
@@ -1352,6 +1353,7 @@ export class Wallets implements IWallets {
                 password: webauthnInfo.passphrase,
                 input: decryptedSharedWalletPrv,
                 encryptionVersion: params.encryptionVersion,
+                adata: walletShare.enterprise,
               }),
             };
           }