diff --git a/holo-key-manager-extension/scripts/helpers.ts b/holo-key-manager-extension/scripts/helpers.ts
index 84bc72e..a1e255c 100644
--- a/holo-key-manager-extension/scripts/helpers.ts
+++ b/holo-key-manager-extension/scripts/helpers.ts
@@ -4,7 +4,7 @@ import {
 	seedBundleReady,
 	UnlockedSeedBundle
 } from '@holochain/hc-seed-bundle';
-import { AUTHENTICATED_APPS_LIST, DEEP_KEY_AGENT_OFFSET, SESSION } from '@shared/const';
+import { AUTHENTICATED_APPS_LIST, DEEP_KEY_AGENT_OFFSET, KEY_INDEX, SESSION } from '@shared/const';
 import { base64ToUint8Array, uint8ArrayToBase64 } from '@shared/helpers';
 import { getDeviceKey, storageService } from '@shared/services';
 import {
@@ -41,13 +41,15 @@ export const signMessageLogic = async ({ message, happId, session }: SignMessage
 	const pw = new TextEncoder().encode(session);
 	const keyUnlocked = cipherList[0].unlock(parseSecret(pw));
 
-	const appKey = keyUnlocked.derive(index + DEEP_KEY_AGENT_OFFSET);
+	const agent = keyUnlocked.derive(index + DEEP_KEY_AGENT_OFFSET);
+	const appKey = agent.derive(KEY_INDEX);
 
 	const uIntArrayMessage = base64ToUint8Array(message);
 
 	const signedMessage = appKey.sign(uIntArrayMessage);
 
 	keyUnlocked.zero();
+	agent.zero();
 	appKey.zero();
 
 	const validatedSchema = SuccessMessageSignedSchema.safeParse({
diff --git a/holo-key-manager-extension/src/lib/const/index.ts b/holo-key-manager-extension/src/lib/const/index.ts
index 29b4a01..c9fa73e 100644
--- a/holo-key-manager-extension/src/lib/const/index.ts
+++ b/holo-key-manager-extension/src/lib/const/index.ts
@@ -1,2 +1 @@
-export const KEY_INDEX = 0;
 export const DEEP_KEY_INDEX = 0;
diff --git a/holo-key-manager-extension/src/lib/helpers/queries.ts b/holo-key-manager-extension/src/lib/helpers/queries.ts
index 9433970..b4daba2 100644
--- a/holo-key-manager-extension/src/lib/helpers/queries.ts
+++ b/holo-key-manager-extension/src/lib/helpers/queries.ts
@@ -2,12 +2,13 @@ import { encodeHashToBase64 } from '@holochain/client';
 import { encode } from '@msgpack/msgpack';
 import type { QueryClient } from '@tanstack/svelte-query';
 
-import { DEEP_KEY_INDEX, KEY_INDEX } from '$const';
+import { DEEP_KEY_INDEX } from '$const';
 import { createGetKeysObjectParams, getKeys, unlockKey } from '$services';
 import {
 	AUTHENTICATED_APPS_LIST,
 	EXTENSION_SESSION_INFO,
 	GET_EXTENSION_SESSION,
+	KEY_INDEX,
 	LOCAL,
 	PASSWORD,
 	SENDER_EXTENSION,
diff --git a/holo-key-manager-extension/static/manifest.json b/holo-key-manager-extension/static/manifest.json
index 542d8a6..422313e 100644
--- a/holo-key-manager-extension/static/manifest.json
+++ b/holo-key-manager-extension/static/manifest.json
@@ -1,7 +1,7 @@
 {
 	"name": "Holo key manager",
 	"description": "A browser extension to manage holo keys",
-	"version": "0.0.70",
+	"version": "0.0.71",
 	"key": "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAiAtKvbHNTN3O2BLRZH7RkLczaMLenSeZu+YP+KomPQPZ18nt4DY9boIN/+GWts7gCzEeQq59l8edGdF2P7xAbsRxYR88+zFEbxMtIyfyqJZIlzXwnvPJkwGu/S6arNtX48K7q1+xnJEE7VyeYSj6/i2LR+LmPigCzY9JCP7+SmWVeYbdm3kZmReK0ecfh15RXSNjZpXJUgrbea/RVxweggYKnmhhOUBmuJSCLoWTXIuJPBMwGQK1O2GKBqHOq94bPVSF7j+4WzSpPan70ZZJX/reFsOFE/idfFN6wbizjR1Ne50Po03kudEmfQgoqUhVpd0wP8A3YbqE7ODdZcCPPwIDAQAB",
 	"manifest_version": 3,
 	"action": {
diff --git a/shared/const/app.ts b/shared/const/app.ts
index ed237da..fd13921 100644
--- a/shared/const/app.ts
+++ b/shared/const/app.ts
@@ -4,6 +4,7 @@ export const SENDER_WEBAPP = 'webapp';
 export const SENDER_EXTENSION = 'extension';
 export const SENDER_BACKGROUND_SCRIPT = 'background-script';
 export const DEEP_KEY_AGENT_OFFSET = 1;
+export const KEY_INDEX = 0;
 
 export const HOLO_KEY_MANAGER_EXTENSION_MARKER_ID = 'user-holo-key-manager-extension-marker';