diff --git a/index.js b/index.js
index 3aff528..50a1f45 100644
--- a/index.js
+++ b/index.js
@@ -41,7 +41,7 @@ const encryption_mode_cbc_128 = {
 /**
  * creates a random string
  *
- * @param {number} len string length default: 6
+ * @param {number} len string length default: 8
  * @returns {string} random string
  */
 function random_string (len = 8) {
diff --git a/package.json b/package.json
index 1d9343e..8d17f2d 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@sapphirecode/crypto-helper",
-  "version": "1.1.61",
+  "version": "1.1.62",
   "main": "index.js",
   "author": {
     "name": "Timo Hocker",
diff --git a/test/spec/index.js b/test/spec/index.js
index eef222c..a6ff525 100644
--- a/test/spec/index.js
+++ b/test/spec/index.js
@@ -28,7 +28,7 @@ describe ('crypto helper', () => {
       .toMatch (/^[0-9a-f]+$/iu);
   });
 
-  it ('random_hex should refuse lenght smaller 1', () => {
+  it ('random_hex should refuse length smaller 1', () => {
     expect (
       () => (crypto.random_hex (0))
     )
@@ -55,7 +55,7 @@ describe ('crypto helper', () => {
       .toEqual (8);
   });
 
-  it ('random_string should refuse lenght smaller 1', () => {
+  it ('random_string should refuse length smaller 1', () => {
     expect (
       () => (crypto.random_string (0))
     )
@@ -126,6 +126,14 @@ describe ('crypto helper', () => {
       .toEqual (dec);
   });
 
+  it ('should reject tampered signatures', () => {
+    const obj = { foo: 'bar' };
+    const str = crypto.sign_object (obj, 'baz');
+    const dec = crypto.verify_signature (str, 'foo');
+    expect (dec)
+      .toEqual (null);
+  });
+
   it ('should return null on invalid input', () => {
     const ver = crypto.verify_signature (null, 'foo');
     expect (ver)
@@ -136,44 +144,86 @@ describe ('crypto helper', () => {
   });
 
   it ('should not fail verification if timeout unspecified', async () => {
+    jasmine.clock ()
+      .install ();
+    const base_time = (new Date);
+    jasmine.clock ()
+      .mockDate (base_time);
+
     const obj = { foo: 'bar' };
     const str = crypto.sign_object (obj, 'baz');
-    await new Promise ((res) => {
-      setTimeout (res, 10);
-    });
+
+    jasmine.clock ()
+      .tick (36e5);
+
     const dec = crypto.verify_signature (str, 'baz');
     expect (obj)
       .toEqual (dec);
-  });
 
-  it ('should reject tampered signatures', () => {
-    const obj = { foo: 'bar' };
-    const str = crypto.sign_object (obj, 'baz');
-    const dec = crypto.verify_signature (str, 'foo');
-    expect (dec)
-      .toEqual (null);
+    jasmine.clock ()
+      .uninstall ();
   });
 
   it ('should reject old signatures', async () => {
+    jasmine.clock ()
+      .install ();
+    const base_time = (new Date);
+    jasmine.clock ()
+      .mockDate (base_time);
+
     const obj = { foo: 'bar' };
     const str = crypto.sign_object (obj, 'baz');
-    await new Promise ((res) => {
-      setTimeout (res, 10);
-    });
+
+    jasmine.clock ()
+      .tick (50);
+
     const dec = crypto.verify_signature (str, 'baz', 1);
     expect (dec)
       .toEqual (null);
+
+    jasmine.clock ()
+      .uninstall ();
   });
 
   it ('should not reject valid signatures', async () => {
+    jasmine.clock ()
+      .install ();
+    const base_time = (new Date);
+    jasmine.clock ()
+      .mockDate (base_time);
+
     const obj = { foo: 'bar' };
     const str = crypto.sign_object (obj, 'baz');
-    await new Promise ((res) => {
-      setTimeout (res, 10);
-    });
+
+    jasmine.clock ()
+      .tick (50);
+
     const dec = crypto.verify_signature (str, 'baz', 100);
     expect (obj)
       .toEqual (dec);
+
+    jasmine.clock ()
+      .uninstall ();
+  });
+
+  it ('verify_signature on almost timed out packet', () => {
+    jasmine.clock ()
+      .install ();
+    const base_time = (new Date);
+    jasmine.clock ()
+      .mockDate (base_time);
+
+    const obj = { foo: 'bar' };
+    const str = crypto.sign_object (obj, 'baz');
+
+    jasmine.clock ()
+      .tick (10);
+    const dec = crypto.verify_signature (str, 'baz', 10);
+    expect (obj)
+      .toEqual (dec);
+
+    jasmine.clock ()
+      .uninstall ();
   });
 
   it ('should decode problematic token', () => {