diff --git a/src/misc.ts b/src/misc.ts
index c9d58a5..adaf799 100644
--- a/src/misc.ts
+++ b/src/misc.ts
@@ -34,3 +34,10 @@ export async function pubkey_fromString(pubkey_str: string, usage: Usage): Promi
     return null
   }
 }
+
+export function payload_fromString(text: string): Uint8Array {
+  return new TextEncoder().encode(text)
+}
+export function payload_toString(payload: Uint8Array): string {
+  return new TextDecoder().decode(payload)
+}
diff --git a/src/private-box.ts b/src/private-box.ts
index 9695f44..9207cfe 100644
--- a/src/private-box.ts
+++ b/src/private-box.ts
@@ -1,8 +1,8 @@
 import logger from 'log'
 import SecretBox from './secret-box'
 import {DHusage, ecdh} from './kdf'
-import {pubkey_fromString, pubkey_toString, Usage} from './misc'
 import * as consts from './const'
+import * as misc from './misc.ts'
 
 const log = logger('crypto:private-box')
 
@@ -39,7 +39,7 @@ export default class PrivateBox {
 
   public async toString(): Promise<string> {
     log.trace('toString')
-    const pubkey = await pubkey_toString(this.pubkey)
+    const pubkey = await PrivateBox.pubkey_toString(this.pubkey)
     const box = this.box.toString()
     return `${pubkey}.${box}`
   }
@@ -49,11 +49,18 @@ export default class PrivateBox {
     const parts = data.split('.')
     if (parts.length < 2) return null
 
-    const pubkey = await pubkey_fromString(parts[0], Usage.ecdh)
+    const pubkey = await PrivateBox.pubkey_fromString(parts[0])
     if (pubkey === null) return null
     const box = SecretBox.fromString(parts.slice(1).join('.'))
     if (box === null) return null
 
     return new PrivateBox(pubkey, box)
   }
+
+  public static pubkey_toString(pubkey: CryptoKey): Promise<string> {
+    return misc.pubkey_toString(pubkey)
+  }
+  public static pubkey_fromString(pubkey: string): Promise<CryptoKey | null> {
+    return misc.pubkey_fromString(pubkey, misc.Usage.ecdh)
+  }
 }
diff --git a/src/private-wrap.ts b/src/private-wrap.ts
index 40ee2c1..a310acd 100644
--- a/src/private-wrap.ts
+++ b/src/private-wrap.ts
@@ -1,7 +1,7 @@
 import logger from 'log'
 import {DHusage, ecdh} from './kdf'
 import SecretWrap from './secret-wrap'
-import {pubkey_fromString, pubkey_toString, Usage} from './misc'
+import * as misc from './misc'
 import * as consts from './const'
 
 const log = logger('crypto:private-wrap')
@@ -32,7 +32,7 @@ export default class PrivateWrap {
 
   public async toString(): Promise<string> {
     log.trace('toString')
-    const pubkey = await pubkey_toString(this.pubkey)
+    const pubkey = await PrivateWrap.pubkey_toString(this.pubkey)
     const box = this.box.toString()
     return `${pubkey}.${box}`
   }
@@ -42,11 +42,18 @@ export default class PrivateWrap {
     const parts = data.split('.')
     if (parts.length < 2) return null
 
-    const pubkey = await pubkey_fromString(parts[0], Usage.ecdh)
+    const pubkey = await PrivateWrap.pubkey_fromString(parts[0])
     if (pubkey === null) return null
     const box = SecretWrap.fromString(parts.slice(1).join('.'))
     if (box === null) return null
 
     return new PrivateWrap(box, pubkey)
   }
+
+  public static pubkey_toString(pubkey: CryptoKey): Promise<string> {
+    return misc.pubkey_toString(pubkey)
+  }
+  public static pubkey_fromString(pubkey: string): Promise<CryptoKey | null> {
+    return misc.pubkey_fromString(pubkey, misc.Usage.ecdh)
+  }
 }
diff --git a/src/signature.ts b/src/signature.ts
index 6e3f154..a307d6e 100644
--- a/src/signature.ts
+++ b/src/signature.ts
@@ -1,6 +1,8 @@
 import logger from 'log'
 const log = logger('crypto:signature')
 import * as consts from './const'
+import * as misc from './misc'
+import * as libmisc from 'misc'
 
 export async function gen(extractable: boolean = true): Promise<CryptoKeyPair> {
   return crypto.subtle.generateKey(consts.SIGNATURE_KEY, extractable, ['sign', 'verify'])
@@ -14,3 +16,17 @@ export async function verify(message: Uint8Array, pubkey: CryptoKey, signature:
   log.trace('verify')
   return crypto.subtle.verify(consts.SIGNATURE_ALGO, pubkey, signature, message)
 }
+
+export function pubkey_toString(pubkey: CryptoKey): Promise<string> {
+  return misc.pubkey_toString(pubkey)
+}
+export async function pubkey_fromString(pubkey: string): Promise<CryptoKey | null> {
+  return misc.pubkey_fromString(pubkey, misc.Usage.sign)
+}
+
+export function signature_toString(signature: Uint8Array): string {
+  return libmisc.a2b64(signature)
+}
+export function signature_fromString(signature: string): Uint8Array | null {
+  return libmisc.b642a(signature)
+}