1# Miden Crypto
 2This crate contains cryptographic primitives used in Polygon Miden.
 3
 4## Hash
 5[Hash module](./src/hash) provides a set of cryptographic hash functions which are used by the Miden VM and the Miden rollup. Currently, these functions are:
 6
 7* [BLAKE3](https://github.com/BLAKE3-team/BLAKE3) hash function with 256-bit, 192-bit, or 160-bit output. The 192-bit and 160-bit outputs are obtained by truncating the 256-bit output of the standard BLAKE3.
 8* [RPO](https://eprint.iacr.org/2022/1577) hash function with 256-bit output. This hash function is an algebraic hash function suitable for recursive STARKs.
 9
10For performance benchmarks of these hash functions and their comparison to other popular hash functions please see [here](./benches/).
11
12## Merkle
13[Merkle module](./src/merkle/) provides a set of data structures related to Merkle trees. All these data structures are implemented using the RPO hash function described above. The data structures are:
14
15* `MerkleTree`: a regular fully-balanced binary Merkle tree. The depth of this tree can be at most 64.
16* `MerklePathSet`: a collection of Merkle authentication paths all resolving to the same root. The length of the paths can be at most 64.
17
18## Crate features
19This crate can be compiled with the following features:
20
21* `std` - enabled by default and relies on the Rust standard library.
22* `no_std` does not rely on the Rust standard library and enables compilation to WebAssembly.
23
24Both of these features imply the use of [alloc](https://doc.rust-lang.org/alloc/) to support heap-allocated collections.
25
26To compile with `no_std`, disable default features via `--no-default-features` flag.
27
28## Testing
29
30You can use cargo defaults to test the library:
31
32```shell
33cargo test
34```
35
36However, some of the functions are heavy and might take a while for the tests to complete. In order to test in release mode, we have to replicate the same test conditions of the development mode so all debug assertions can be verified.
37
38We do that by enabling some special [flags](https://doc.rust-lang.org/cargo/reference/profiles.html) for the compilation.
39
40```shell
41RUSTFLAGS="-C debug-assertions -C overflow-checks -C debuginfo=2" cargo test --release
42```
43
44## License
45This project is [MIT licensed](./LICENSE).