Added copyright information.

README.md

@@ -15,3 +15,17 @@ Prototype software, use at your own peril.
 
 This library is free and open-source software released under the MIT
 license.
+
+# Copyright
+
+BitcoinJS (c) 2011-2012 Stefan Thomas
+Released under MIT license
+http://bitcoinjs.org/
+
+JSBN (c) 2003-2005 Tom Wu
+Released under BSD license
+http://www-cs-students.stanford.edu/~tjw/jsbn/
+
+CryptoJS (c) 2009–2012 by Jeff Mott
+Released under New BSD license
+http://code.google.com/p/crypto-js/