Trait HashToGroup 

pub trait HashToGroup: CryptoGroup {
    // Required method
    fn hash_to_group(domain_separator: &[u8], message: &[u8]) -> Self;

    // Provided method
    fn rand_to_group(rng: impl CryptoRngCore) -> Self { ... }
}

A CryptoGroup which supports obliviously sampling elements.

This capability is also often referred to as “hash to curve”, in the context of Elliptic Curve Cryptography, but we use the term “group” to match the naming conventions for other traits.

Advanced protocols use this capability to create new generator elements whose discrete logarithm relative to other points is unknown.

Required Methods

fn hash_to_group(domain_separator: &[u8], message: &[u8]) -> Self

Hash a domain separator, and a message, returning a group element.

This should return an element without knowing its discrete logarithm.

In particular, hashing into a CryptoGroup::Scalar, and then multiplying that by CryptoGroup::generator DOES NOT work.

Provided Methods

fn rand_to_group(rng: impl CryptoRngCore) -> Self

Convert randomness to a group element, without learning its discrete logarithm.

This has a default implementation assuming 128 bits of collision security. This works by generating 256 bits of randomness, and then passing that to HashToGroup::hash_to_group.

If you have a more efficient implementation, or want more collision security, override this method.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors