Ming Ke Ming (名可名) -- Account Module (Dart)

This document introduces a common Account Module for decentralized user identity authentication.

Copyright © 2023 Albert Moky

Features

Meta

The Meta was generated by your private key, it can be used to build a new ID for entity, or verify the ID/PK pair.

It consists of 4 fields:

Field	Description
type	Meta Algorithm Version
key	Public Key
seed	Entity Name
fingerprint	Signature to generate address

ID

The ID is used to identify an entity(user/group). It consists of 3 fields:

Field	Description
type	Entity type
name	Same with meta.seed
address	Unique Identification
terminal	Login point, it's optional.

The ID format is name@address[/terminal].

Usage

Meta

/* Meta(JsON) for hulk@4YeVEN3aUnvC1DNUufCq1bs9zoBSJTzVEj */
{
    "version"     : 0x01,
    "key"         : {
        "algorithm" : "RSA",
        "data"      : "-----BEGIN PUBLIC KEY-----\nMIGJAoGBALB+vbUK48UU9rjlgnohQowME+3JtTb2hLPqtatVOW364/EKFq0/PSdnZVE9V2Zq+pbX7dj3nCS4pWnYf40ELH8wuDm0Tc4jQ70v4LgAcdy3JGTnWUGiCsY+0Z8kNzRkm3FJid592FL7ryzfvIzB9bjg8U2JqlyCVAyUYEnKv4lDAgMBAAE=\n-----END PUBLIC KEY-----",
        "mode"      : "ECB",
        "padding"   : "PKCS1",
        "digest"    : "SHA256"
    },
    "seed"        : "hulk",
    "fingerprint" : "jIPGWpWSbR/DQH6ol3t9DSFkYroVHQDvtbJErmFztMUP2DgRrRSNWuoKY5Y26qL38wfXJQXjYiWqNWKQmQe/gK8M8NkU7lRwm+2nh9wSBYV6Q4WXsCboKbnM0+HVn9Vdfp21hMMGrxTX1pBPRbi0567ZjNQC8ffdW2WvQSoec2I="
}

Meta Type

• 0x01 Default version
• 0x02 BTC version
• 0x03 Extended BTC version
• 0x04 ETH version
• 0x05 Extended ETH version

ID

# ID examples
ID1 = "hulk@4YeVEN3aUnvC1DNUufCq1bs9zoBSJTzVEj";  // Immortal Hulk
ID2 = "moki@4WDfe3zZ4T7opFSi3iDAKiuTnUHjxmXekk";  // Monkey King

ID Name

The Name field is a username, or just a random string for group:

1. The length of name must more than 1 byte, less than 32 bytes;
2. It should be composed by a-z, A-Z, 0-9, or charactors '_', '-', '.';
3. It cannot contain key charactors('@', '/').

# Name examples
user_name  = "Albert.Moky";
group_name = "Group-9527";

ID Address

The Address field was created with the Fingerprint in Meta and a Network ID:

public final class BTCAddress extends Address {

    private static byte[] checkCode(byte[] data) {
        byte[] sha256d = SHA256.digest(SHA256.digest(data));
        byte[] cc = new byte[4];
        System.arraycopy(sha256d, 0, cc, 0, 4);
        return cc;
    }

    private static long userNumber(byte[] cc) {
        return (long)(cc[3] & 0xFF) << 24 | (cc[2] & 0xFF) << 16 | (cc[1] & 0xFF) << 8 | (cc[0] & 0xFF);
    }

    static BTCAddress generate(byte[] fingerprint, NetworkType network) {
        // 1. digest = ripemd160(sha256(fingerprint))
        byte[] digest = RIPEMD160.digest(SHA256.digest(fingerprint));
        // 2. head = network + digest
        byte[] head = new byte[21];
        head[0] = network.toByte();
        System.arraycopy(digest, 0, head, 1, 20);
        // 3. cc = sha256(sha256(head)).prefix(4)
        byte[] cc = checkCode(head);
        // 4. data = base58_encode(head + cc)
        byte[] data = new byte[25];
        System.arraycopy(head, 0, data, 0, 21);
        System.arraycopy(cc,0, data, 21, 4);
        return new BTCAddress(Base58.encode(data));
    }
}

When you get a meta for the entity ID from the network, you must verify it with the consensus algorithm before accepting its public key.

(All data encode with BASE64 algorithm as default, excepts the address)