Base64 is not an encryption algorithm - it is a translation algorithm. The difference being that encryption is secure, and translation isn't...
Base64 is simple, and converts binary 8 bit data into a form that is transmittable over a character based data link such as HTML which does not support binary. It in no way encrypts data, and it can be reversed with ease by even novice coders. There is a good explanation here: http://en.wikipedia.org/wiki/Base64