PktSeed

This is the seed algorithm used in PktWallet.

Why another seed algotithm?!

1. Versions: BIP-39 has no version so it cannot be updated, ever
2. Encryption: Seeds can optionally be encrypted using a passphrase stretched with Argon2 for significant additional safety. BIP-39 also allows a passphrase, but the passphrase is hashed with the seed rather than being used to encrypt it, so a BIP-39 passphrase can never be changed but a PKT passphrase can be changed any time and will simply result in a new word-based representation of the seed.
3. Checksums: A single wrong word is quickly detected without a confusing decryption failure. The birthday also serves as an additional few bits of checksum because seeds which declare a birthday from before this seed algorithm was first released, or one in the future, are rejected.
4. Birthdays: Seeds contain a datestamp with the day when the seed (wallet) was created, so wallet implementations can re-sync from seed without scanning the entire history of the blockchain.
5. Convention Over Configuration: All PKT seed phrases are exactly 15 words long and provide 136 bits of security, a security level which is recognized as adaquate in the cryptography community. BIP-39 defines 12, 15, 18, 21 and 24 word seeds, punting the question of appropriate security level to the end users, many of whom would select 200 word seeds if they were so offered.

How do I?

Make an encrypted seed and output the words

use rand::Rng;
use pktseed::{Seed, SeedEnc};
fn main() {
    let mut rng = rand::thread_rng();
    let seed = Seed::new(rng.gen::<[u8; 17]>());
    let seed_enc = seed.encrypt(Some(b"password"));
    println!("Encrypted seed words: {}", seed_enc.words("english"));
}

Make an unencrypted seed

use rand::Rng;
use pktseed::{Seed, SeedEnc};
fn main() {
    let mut rng = rand::thread_rng();
    let seed = Seed::new(rng.gen::<[u8; 17]>());
    let seed_enc = seed.encrypt(None);
    println!("Unencrypted seed words: {}", seed_enc.words("english"));
}

Check if a seed is encrypted

use pktseed::SeedEnc;
fn main() {
    let seed_enc = SeedEnc::from_words(
        "mom blanket bulk draw clip wolf bread erupt merry skin cable infant word exchange animal",
    ).unwrap();
    println!("Is seed encrypted? {}", seed_enc.is_encrypted());
}

Decrypt seed

use pktseed::SeedEnc;
fn main() {
    let seed_enc = SeedEnc::from_words(
        "mom blanket bulk draw clip wolf bread erupt merry skin cable infant word exchange animal",
    ).unwrap();
    let seed = seed_enc.decrypt(b"password", false).unwrap();
    println!("Decrypted seed bytes: {}", hex::encode(&seed.bytes[..]));
}

C API

Re-generating header: cargo build --release --features generate-capi

Languages

To compile with additional language support you can use:

cargo build --release --features lang-spanish lang-french lang-czech

License

Apache2 OR MIT, at your option.