keyczar_util.js
function _unpackOutput(message) {
    if (message.charAt(0) != keyczar_util.VERSION_BYTE) {
        throw new Error('Unsupported version byte: ' + message.charCodeAt(0));
    }

    var keyhash = message.substr(1, keyczar_util.KEYHASH_LENGTH);
    message = message.substr(1 + keyczar_util.KEYHASH_LENGTH);
    return {keyhash: keyhash, message: message};
}
function _unpackOutput(message) {
    if (message.charAt(0) != keyczar_util.VERSION_BYTE) {
        throw new Error('Unsupported version byte: ' + message.charCodeAt(0));
    }

    var keyhash = message.substr(1, keyczar_util.KEYHASH_LENGTH);
    message = message.substr(1 + keyczar_util.KEYHASH_LENGTH);
    return {keyhash: keyhash, message: message};
}
Unpacks Keyczar's output format