diff --git a/lib/SIN.js b/lib/SIN.js
index 314db84..53889f0 100644
--- a/lib/SIN.js
+++ b/lib/SIN.js
@@ -1,6 +1,8 @@
+'use strict';
 var VersionedData = require('../util/VersionedData');
 var EncodedData = require('../util/EncodedData');
 var util = require('util');
+var coinUtil = require('../util');
 
 function SIN(type, payload) {
   if (typeof type != 'number') {
@@ -62,4 +64,18 @@ SIN.prototype.validate = function() {
     if (this.data.length != 22) throw new Error('invalid data length');
   });
 };
+
+
+// create a SIN from a public key
+SIN.fromPubKey = function(pubKey, type) {
+  if (!type)
+    type = SIN.SIN_EPHEM;
+
+  if (!Buffer.isBuffer(pubKey) || pubKey.length !== 33)
+    throw new Error('Invalid public key' + pubKey.length);
+
+  var hash = coinUtil.sha256ripe160(pubKey);
+  return new SIN(hash, type);
+};
+
 module.exports = SIN;
diff --git a/test/test.SIN.js b/test/test.SIN.js
index d84b223..1094727 100644
--- a/test/test.SIN.js
+++ b/test/test.SIN.js
@@ -21,6 +21,8 @@ describe('SIN', function() {
   });
   var data = [
     ['6bqov85Hsatqb8eLtwLW1PBQLWVNJkzPwgdAT3SYNkB6X2aF2n', false],
+    ['TfGPWmEYZCTr1FHqinjoGxnYAxdBhsta4qR', true],
+    ['TexvSXam8vtoUviGajQyDuYdPSAEtwTNyZg', true]
   ];
   data.forEach(function(datum) {
     var sin = datum[0];
@@ -28,7 +30,6 @@ describe('SIN', function() {
     it('should validate correctly ' + sin, function() {
       var a = new SIN(sin);
       var s = a.toString();
-
       a.isValid().should.equal(result);
       s.should.equal(a.toString()); // check that validation doesn't change data
     });
@@ -36,14 +37,27 @@ describe('SIN', function() {
 
   describe('#SIN', function() {
     it('should be able to create a new SIN with a version byte', function() {
-      var myhash = bitcore.util.sha256ripe160('test');
+      var myhash = bitcore.util.sha256ripe160('test123123');
       var sin = new SIN(SIN.SIN_EPHEM, myhash);
       should.exist(sin);
     });
   });
+  describe('#fromPubKey', function() {
+    it('should fail to create  a new SIN not using a pub key', function() {
+      (function() { SIN.fromPubKey('1234')}).should.throw();
+    });
+    it('should fail to create  a new SIN not using a pub key case 2', function() {
+      (function() { SIN.fromPubKey('X2345678901234567890123456789012112345678901234567890123456781011')}).should.throw();
+    });
+    it('should be able to create a new SIN using a pub key', function() {
+      var pubkey1 = new Buffer('03e0973263b4e0d5f5f56d25d430e777ab3838ff644db972c0bf32c31da5686c27', 'hex');
+      var sin = SIN.fromPubKey(pubkey1);
+      should.exist(sin);
+      sin.toString().should.equal('FrCfKjSFN1Ubp3x6AD6au8M5LTaNAEN8b');
+    });
+ 
+  });
 });
 
 
 
-
-