diff --git a/package-lock.json b/package-lock.json
index 140baaf71..b3b4e8308 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -18762,6 +18762,11 @@
         "node": ">= 0.8.0"
       }
     },
+    "node_modules/tweetnacl": {
+      "version": "1.0.3",
+      "resolved": "https://registry.npmjs.org/tweetnacl/-/tweetnacl-1.0.3.tgz",
+      "integrity": "sha512-6rt+RN7aOi1nGMyC4Xa5DdYiukl2UWCbcJft7YhxReBGQD7OAM8Pbxw6YMo4r2diNEA8FEmu32YOn9rhaiE5yw=="
+    },
     "node_modules/tx2": {
       "version": "1.0.5",
       "dev": true,
@@ -20843,7 +20848,8 @@
         "@noble/hashes": "^1.3.1",
         "bip39": "^3.0.4",
         "bs58check": "^2.1.2",
-        "secp256k1": "^4.0.3"
+        "secp256k1": "^4.0.3",
+        "tweetnacl": "^1.0.3"
       },
       "devDependencies": {
         "@types/bs58check": "^2.1.0",
diff --git a/packages/agent/tsconfig.json b/packages/agent/tsconfig.json
index 325cd0b3b..5d74a0447 100644
--- a/packages/agent/tsconfig.json
+++ b/packages/agent/tsconfig.json
@@ -24,5 +24,5 @@
     "tsBuildInfoFile": "./build_info.json"
   },
   "include": ["types/*", "src/**/*.ts", "../candid/src/utils/bls.test.ts"],
-  "exclude": ["**/src/**/__certificates__/**"]
+  "exclude": ["**/src/**/__certificates__/**", "**/src/**/*.test.ts"]
 }
diff --git a/packages/identity-secp256k1/package.json b/packages/identity-secp256k1/package.json
index 9d10f62a0..8afd28583 100644
--- a/packages/identity-secp256k1/package.json
+++ b/packages/identity-secp256k1/package.json
@@ -18,7 +18,8 @@
     "@noble/hashes": "^1.3.1",
     "bip39": "^3.0.4",
     "bs58check": "^2.1.2",
-    "secp256k1": "^4.0.3"
+    "secp256k1": "^4.0.3",
+    "tweetnacl": "^1.0.3"
   },
   "devDependencies": {
     "@types/bs58check": "^2.1.0",
diff --git a/packages/identity/src/identity/webauthn.ts b/packages/identity/src/identity/webauthn.ts
index 47ecd8a9e..63216465a 100644
--- a/packages/identity/src/identity/webauthn.ts
+++ b/packages/identity/src/identity/webauthn.ts
@@ -1,8 +1,15 @@
-import { DerEncodedPublicKey, PublicKey, Signature, SignIdentity } from '@dfinity/agent';
+import {
+  DerEncodedPublicKey,
+  PublicKey,
+  Signature,
+  SignIdentity,
+  wrapDER,
+  DER_COSE_OID,
+  fromHex,
+  toHex,
+} from '@dfinity/agent';
 import borc from 'borc';
-import { fromHexString, toHexString } from '../buffer';
 import { randomBytes } from '@noble/hashes/utils';
-import { DER_COSE_OID, wrapDER } from './der';
 
 function _coseToDerEncodedBlob(cose: ArrayBuffer): DerEncodedPublicKey {
   return wrapDER(cose, DER_COSE_OID).buffer as DerEncodedPublicKey;
@@ -132,7 +139,7 @@ export class WebAuthnIdentity extends SignIdentity {
       throw new Error('Invalid JSON string.');
     }
 
-    return new this(fromHexString(rawId), fromHexString(publicKey), undefined);
+    return new this(fromHex(rawId), fromHex(publicKey), undefined);
   }
 
   /**
@@ -234,8 +241,8 @@ export class WebAuthnIdentity extends SignIdentity {
    */
   public toJSON(): JsonnableWebAuthnIdentity {
     return {
-      publicKey: toHexString(this._publicKey.getCose()),
-      rawId: toHexString(this.rawId),
+      publicKey: toHex(this._publicKey.getCose()),
+      rawId: toHex(this.rawId),
     };
   }
 }
diff --git a/packages/identity/src/index.ts b/packages/identity/src/index.ts
index e00d8780e..a07f304a6 100644
--- a/packages/identity/src/index.ts
+++ b/packages/identity/src/index.ts
@@ -2,7 +2,7 @@ export { Ed25519KeyIdentity, Ed25519PublicKey } from './identity/ed25519';
 export * from './identity/ecdsa';
 export * from './identity/delegation';
 export { WebAuthnIdentity } from './identity/webauthn';
-export { wrapDER, unwrapDER, DER_COSE_OID, ED25519_OID } from './identity/der';
+export { wrapDER, unwrapDER, DER_COSE_OID, ED25519_OID } from '@dfinity/agent';
 
 /**
  * @deprecated due to size of dependencies. Use `@dfinity/identity-secp256k1` instead.