# seed-xor

seed-xor builds on top of [rust-bip39](https://github.com/rust-bitcoin/rust-bip39/)
and lets you XOR bip39 mnemonics as described in [Coldcards docs](https://github.com/Coldcard/firmware/blob/master/docs/seed-xor.md).


It is also possible to XOR mnemonics with differing numbers of words.
For this the shorter one will be extended with the longer one's surplus entropy.


## Example

```rust
use seed_xor::Mnemonic;
use std::str::FromStr;

// Coldcard example: https://github.com/Coldcard/firmware/blob/master/docs/seed-xor.md
let a_str = "romance wink lottery autumn shop bring dawn tongue range crater truth ability miss spice fitness easy legal release recall obey exchange recycle dragon room";
let b_str = "lion misery divide hurry latin fluid camp advance illegal lab pyramid unaware eager fringe sick camera series noodle toy crowd jeans select depth lounge";
let c_str = "vault nominee cradle silk own frown throw leg cactus recall talent worry gadget surface shy planet purpose coffee drip few seven term squeeze educate";
let result_str = "silent toe meat possible chair blossom wait occur this worth option bag nurse find fish scene bench asthma bike wage world quit primary indoor";

// Mnemonic is a wrapper for bip39::Mnemonic which implements the XOR operation `^`.
// Mnemonics can also be created from entropy.
let a = Mnemonic::from_str(a_str).unwrap();
let b = Mnemonic::from_str(b_str).unwrap();
let c = Mnemonic::from_str(c_str).unwrap();
let result = Mnemonic::from_str(result_str).unwrap();

assert_eq!(result, a ^ b ^ c);
```

 ## Useful resources
 - Coldcard docs: https://github.com/Coldcard/firmware/blob/master/docs/seed-xor.md
 - Easy bip39 mnemonic explanation: https://learnmeabitcoin.com/technical/mnemonic