An implementation of Base58 and Base58Check encodings for nodejs. Note, the implementation of Base58Check differs slightly from that described on Wikipedia in that it does not prepend a version byte onto the data being encoded. This implementation uses a native module and big numbers from openssl.

npm install base58-native

var base58 = require('base58-native');
base58.encode(base58.decode('mqqa8xSMVDyf9QxihGnPtap6Mh6qemUkcu'));

var base58Check = require('base58-native').base58Check;
base58Check.encode(base58Check.decode('mqqa8xSMVDyf9QxihGnPtap6Mh6qemUkcu'));