var Q = require('q')
  , crypto = require('crypto');

module.exports = function(bytes) {
    var q = Q.defer();
    crypto.randomBytes(bytes || 8, function(ex, buf) {
        if ( ex ) {
            q.reject(ex);
        } else {
            q.resolve(buf.toString('hex'));
        }
    });
    return q.promise;
};