diff --git a/.gitignore b/.gitignore
index a9f4ed5..1ca9571 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,2 @@
-lib
-node_modules
\ No newline at end of file
+node_modules/
+npm-debug.log
diff --git a/.npmignore b/.npmignore
deleted file mode 100644
index 6bd575e..0000000
--- a/.npmignore
+++ /dev/null
@@ -1,2 +0,0 @@
-.travis.yml
-tests
\ No newline at end of file
diff --git a/.travis.yml b/.travis.yml
index 92a1e92..10d8531 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,3 +1,3 @@
 language: node_js
 node_js:
-  - 4
\ No newline at end of file
+  - 6
\ No newline at end of file
diff --git a/index.js b/index.js
index da82a42..bdfe301 100644
--- a/index.js
+++ b/index.js
@@ -9,6 +9,7 @@ module.exports = {
     _string2charCodes,
     _getCharType,
     _getPasswordChar,
+    _createHmac
 };
 
 function _encryptLogin(login, masterPassword) {
@@ -29,15 +30,23 @@ function _encryptLogin(login, masterPassword) {
 }
 
 function _renderPassword(encryptedLogin, site, passwordOptions) {
-    const derivedEncryptedLogin = this._deriveEncryptedLogin(encryptedLogin, site, passwordOptions);
-    const template = this._getPasswordTemplate(passwordOptions);
-    return this._prettyPrint(derivedEncryptedLogin, template);
+    return _deriveEncryptedLogin(encryptedLogin, site, passwordOptions).then(function (derivedEncryptedLogin) {
+        const template = _getPasswordTemplate(passwordOptions);
+        return _prettyPrint(derivedEncryptedLogin, template);
+    });
+}
+
+function _createHmac(encryptedLogin, salt) {
+    return new Promise(resolve => {
+        resolve(crypto.createHmac('sha256', encryptedLogin).update(salt).digest('hex'));
+    });
 }
 
 function _deriveEncryptedLogin(encryptedLogin, site, passwordOptions = {length: 12, counter: 1}) {
     const salt = site + passwordOptions.counter.toString();
-    const derivedHash = crypto.createHmac('sha256', encryptedLogin).update(salt).digest('hex');
-    return derivedHash.substring(0, passwordOptions.length);
+    return _createHmac(encryptedLogin, salt).then(derivedHash => {
+        return derivedHash.substring(0, passwordOptions.length);
+    });
 }
 
 function _getPasswordTemplate(passwordTypes) {
@@ -59,9 +68,9 @@ function _getPasswordTemplate(passwordTypes) {
 function _prettyPrint(hash, template) {
     let password = '';
 
-    this._string2charCodes(hash).forEach((charCode, index) => {
-        const charType = this._getCharType(template, index);
-        password += this._getPasswordChar(charType, charCode);
+    _string2charCodes(hash).forEach((charCode, index) => {
+        const charType = _getCharType(template, index);
+        password += _getPasswordChar(charType, charCode);
     });
     return password;
 }
diff --git a/package.json b/package.json
index bc17313..aba9245 100644
--- a/package.json
+++ b/package.json
@@ -1,19 +1,21 @@
 {
   "name": "lesspass",
-  "version": "4.0.4",
+  "version": "5.0.0",
   "author": "Guillaume Vincent <guillaume@oslab.fr>",
-  "description": "LessPass javascript module to generate idempotent passwords",
+  "description": "LessPass node module used to generate LessPass passwords",
   "main": "lib/index.js",
   "jsnext:main": "index.js",
   "repository": "lesspass/core",
-  "homepage": "https://github.com/lesspass/core#readme",
-  "bugs": "https://github.com/lesspass/core/issues",
   "scripts": {
-    "test-node": "cd tests && babel-node --presets es2015 node.js && cd ..",
+    "test:node": "npm run build && cd tests && babel-node --presets es2015 node.js && cd ..",
     "test": "ava --require babel-core/register",
     "build": "rimraf lib && babel index.js -d lib",
     "prepublish": "npm test && npm run build"
   },
+  "files": [
+    "lib/",
+    "index.js"
+  ],
   "keywords": [
     "password",
     "crypto",
diff --git a/readme.md b/readme.md
index 93c270a..aab81fd 100644
--- a/readme.md
+++ b/readme.md
@@ -4,7 +4,7 @@
 
 ## Requirements
 
-  - node v4.6.x
+  - node LTS v6
 
 ## Install
 
@@ -12,12 +12,12 @@
 
 ## Usage
     
-    import LessPass from 'lesspass';
-        
-    const site = 'lesspass.com';
-    const login = 'contact@lesspass.com';
-    const masterPassword = 'password';
-    const options = {
+    var LessPass = require('lesspass');
+    
+    var site = 'lesspass.com';
+    var login = 'contact@lesspass.com';
+    var masterPassword = 'password';
+    var options = {
         counter: 1,
         length: 12,
         lowercase: true,
@@ -25,11 +25,12 @@
         numbers: true,
         symbols: true
     };
-    LessPass.encryptLogin(login, masterPassword)
-        .then(encryptedLogin => {
-            var generatedPassword = LessPass.renderPassword(encryptedLogin, site, options);
-            console.log(generatedPassword); //azYS7,olOL2]
+    
+    LessPass.encryptLogin(login, masterPassword).then(encryptedLogin => {
+        LessPass.renderPassword(encryptedLogin, site, options).then(generatedPassword => {
+             console.log(generatedPassword); //azYS7,olOL2]
         });
+    });
 
 
 see [tests/api.tests.js](tests/api.tests.js) for more examples
diff --git a/tests/api.tests.js b/tests/api.tests.js
index 654724d..d753b81 100644
--- a/tests/api.tests.js
+++ b/tests/api.tests.js
@@ -1,36 +1,20 @@
 import test from 'ava';
 import lesspass from '../index';
 
-test('encrypt login with pbkdf2 8192 iterations and sha256', t => {
-    return lesspass.encryptLogin('test@example.org', 'password').then(encryptedLogin => {
+test('should use pbkdf2 with 8192 iterations and sha256', t=> {
+    lesspass.encryptLogin('test@example.org', 'password').then(function (encryptedLogin) {
         t.is('d8af5f918db6b65b1db3d3984e5a400e39e1dbb19462220e4431de283809f472', encryptedLogin);
-    })
-});
-
-test('encrypt login with utf8 parameter', t => {
-    return lesspass.encryptLogin('test@example.org', '♥ LessPass ♥').then(encryptedLogin => {
-        t.is('063092c809334979f505df88ed37845d298c01f7e8a03cbd661edbc084c650ca', encryptedLogin);
-    })
+    });
 });
 
-test('render password', t => {
-    const site = 'lesspass.com';
-    const encryptedLogin = '63d850713d0b2f7f2c4396fe93f4ac0c6bc7485f9e7473c4b8c4a33ec12199c0';
-    const passwordOptions = {
-        counter: 1,
-        length: 12,
-        lowercase: true,
-        uppercase: true,
-        numbers: true,
-        symbols: true
-    };
-    t.is('azYS7,olOL2]', lesspass.renderPassword(encryptedLogin, site, passwordOptions));
+test('should allow utf8 parameter', t=> {
+    lesspass.encryptLogin('test@example.org', '♥ LessPass ♥').then(function (encryptedLogin) {
+        t.is('997fe81d3d0db236e039c75efdb487f17a902fdf94f9dacaa9884329c85d9651', encryptedLogin);
+    });
 });
-
-
 test('auto generated encrypt login tests', t => {
-    const promises = [];
-    const passwords = [
+    var promises = [];
+    var passwords = [
         {
             login: 'contact@lesspass.com',
             masterPassword: 'password',
@@ -88,20 +72,34 @@ test('auto generated encrypt login tests', t => {
         }
     ];
 
-    for (const entry of passwords) {
+    for (var entry of passwords) {
         promises.push(lesspass.encryptLogin(entry.login, entry.masterPassword));
     }
 
-    t.plan(passwords.length);
     return Promise.all(promises).then(values => {
         for (let i = 0; i < values.length; i++) {
             t.is(passwords[i].encryptedLogin, values[i]);
         }
     });
 });
-
-test('auto generated derive encrypted login tests', t => {
-    const passwords = [
+test('render password', t => {
+    var site = 'lesspass.com';
+    var encryptedLogin = '63d850713d0b2f7f2c4396fe93f4ac0c6bc7485f9e7473c4b8c4a33ec12199c0';
+    var passwordOptions = {
+        counter: 1,
+        length: 12,
+        lowercase: true,
+        uppercase: true,
+        numbers: true,
+        symbols: true
+    };
+    lesspass.renderPassword(encryptedLogin, site, passwordOptions).then(function (generatedPassword) {
+        t.is('azYS7,olOL2]', generatedPassword);
+    })
+});
+test('auto generated render password tests', t => {
+    var promises = [];
+    var passwords = [
         {
             encryptedLogin: '63d850713d0b2f7f2c4396fe93f4ac0c6bc7485f9e7473c4b8c4a33ec12199c0',
             site: 'lesspass.com',
@@ -225,18 +223,22 @@ test('auto generated derive encrypted login tests', t => {
         }
     ];
 
-
-    t.plan(passwords.length);
-    for (let i = 0; i < passwords.length; i++) {
-        let password = passwords[i];
-        let passwordOption = {
-            counter: password.counter,
-            length: password.length,
-            lowercase: password.lowercase,
-            uppercase: password.uppercase,
-            numbers: password.numbers,
-            symbols: password.symbols,
+    for (var entry of passwords) {
+        var passwordOption = {
+            counter: entry.counter,
+            length: entry.length,
+            lowercase: entry.lowercase,
+            uppercase: entry.uppercase,
+            numbers: entry.numbers,
+            symbols: entry.symbols,
         };
-        t.is(password.generatedPassword, lesspass.renderPassword(password.encryptedLogin, password.site, passwordOption));
+        promises.push(lesspass.renderPassword(entry.encryptedLogin, entry.site, passwordOption));
     }
+
+    return Promise.all(promises).then(values => {
+        for (let i = 0; i < values.length; i++) {
+            t.is(passwords[i].generatedPassword, values[i]);
+        }
+    });
 });
+
diff --git a/tests/deriveEncryptedLogin.tests.js b/tests/deriveEncryptedLogin.tests.js
index 79ad944..002954c 100644
--- a/tests/deriveEncryptedLogin.tests.js
+++ b/tests/deriveEncryptedLogin.tests.js
@@ -1,12 +1,13 @@
 import test from 'ava';
 import lesspass from '../index';
 
-test('should derive encrypted login with default length', t => {
-    const encryptedLogin = '9f505f3a95fe0485da3242cb81c9fe25c2f400d8399737655a8dad2b52778d88';
-    const site = 'lesspass.com';
-    t.is(12, lesspass._deriveEncryptedLogin(encryptedLogin, site).length);
+test('should createHmac', t => {
+    var encryptedLogin = '9f505f3a95fe0485da3242cb81c9fe25c2f400d8399737655a8dad2b52778d88';
+    var salt = 'lesspass.com1';
+    return lesspass._createHmac(encryptedLogin, salt).then(hmac => {
+        t.is('be00f942fc8aa67d8e76fc2456862b9d66d166ebfdd3dc2f0116e278209532ed', hmac);
+    });
 });
-
 test('should derive encrypted login with default options', t => {
     const encryptedLogin = '90cff82b8847525370a8f29a59ecf45db62c719a535788ad0df58d32304e925d';
     const site = 'lesspass.com';
@@ -18,30 +19,32 @@ test('should derive encrypted login with default options', t => {
         numbers: true,
         symbols: true,
     };
-    t.is(
-        lesspass._deriveEncryptedLogin(encryptedLogin, site),
-        lesspass._deriveEncryptedLogin(encryptedLogin, site, option)
-    );
+    var p1 = lesspass._deriveEncryptedLogin(encryptedLogin, site);
+    var p2 = lesspass._deriveEncryptedLogin(encryptedLogin, site, option);
+    Promise.all([p1, p2]).then(generatedPasswords => {
+        t.is(generatedPasswords[0], generatedPasswords[1])
+    });
 });
-
 test('should derive encrypted login with defined length', t => {
-    const encryptedLogin = 'd79d8482f708122288af7b259393a58fe05840f4555cc935cdd3f062b9aa75ed';
-    const site = 'lesspass.com';
-    const option = {
+    var encryptedLogin = 'd79d8482f708122288af7b259393a58fe05840f4555cc935cdd3f062b9aa75ed';
+    var site = 'lesspass.com';
+    var option = {
         counter: 1,
         length: 10,
     };
-    t.is(10, lesspass._deriveEncryptedLogin(encryptedLogin, site, option).length);
+    return lesspass._deriveEncryptedLogin(encryptedLogin, site, option).then(function (generatedPassword) {
+        t.is(10, generatedPassword.length);
+    })
 });
-
 test('should return two different passwords if site different', t => {
     const encryptedLogin = 'f4fd3885fb70085f2285c3382e2d9adb4c2553285fc45dd896791aa5e79070a9';
     const site = 'google.com';
     const site2 = 'facebook.com';
-    t.not(
-        lesspass._deriveEncryptedLogin(encryptedLogin, site),
-        lesspass._deriveEncryptedLogin(encryptedLogin, site2)
-    );
+    var p1 = lesspass._deriveEncryptedLogin(encryptedLogin, site);
+    var p2 = lesspass._deriveEncryptedLogin(encryptedLogin, site2);
+    Promise.all([p1, p2]).then(derivedEncryptedLogins => {
+        t.not(derivedEncryptedLogins[0], derivedEncryptedLogins[1])
+    });
 });
 
 test('should return two different passwords if counter different', t => {
@@ -49,14 +52,17 @@ test('should return two different passwords if counter different', t => {
     const site = 'lesspass.com';
     const option = {counter: 1};
     const option2 = {counter: 2};
-    t.not(
-        lesspass._deriveEncryptedLogin(encryptedLogin, site, option),
-        lesspass._deriveEncryptedLogin(encryptedLogin, site, option2)
-    );
+    var p1 = lesspass._deriveEncryptedLogin(encryptedLogin, site, option);
+    var p2 = lesspass._deriveEncryptedLogin(encryptedLogin, site, option2);
+    Promise.all([p1, p2]).then(derivedEncryptedLogins => {
+        t.not(derivedEncryptedLogins[0], derivedEncryptedLogins[1])
+    });
 });
 
 test('should derive encrypted login with sha 256', t => {
     const encryptedLogin = '9f505f3a95fe0485da3242cb81c9fe25c2f400d8399737655a8dad2b52778d88';
     const site = 'lesspass.com';
-    t.is('be00f942fc8a', lesspass._deriveEncryptedLogin(encryptedLogin, site));
+    return lesspass._deriveEncryptedLogin(encryptedLogin, site).then(function (encryptedLogin) {
+        t.is('be00f942fc8a', encryptedLogin);
+    });
 });
diff --git a/tests/node.js b/tests/node.js
index e5b15a1..a148b28 100644
--- a/tests/node.js
+++ b/tests/node.js
@@ -1,4 +1,4 @@
-var lesspass = require('../lib/index');
+var LessPass = require('../lib/index');
 var assert = require('assert');
 
 var site = 'lesspass.com';
@@ -13,13 +13,13 @@ var options = {
     symbols: true
 };
 
-var generatedPassword;
-lesspass.encryptLogin(login, masterPassword)
-    .then(function (encryptedLogin) {
-        generatedPassword = lesspass.renderPassword(encryptedLogin, site, options);
-        assert.equal(generatedPassword, 'azYS7,olOL2]');
-        console.log('generated password ok');
+LessPass.encryptLogin(login, masterPassword)
+    .then(encryptedLogin => {
+        LessPass.renderPassword(encryptedLogin, site, options).then(generatedPassword => {
+            assert.equal(generatedPassword, 'azYS7,olOL2]');
+            console.log('generated password ok');
+        });
     })
     .catch(e => {
         console.log(e);
-    });
+    });
\ No newline at end of file