Developer Guide

Group Trait

At the core of dlog-group is the Group trait, which defines the behavior expected from any prime-order group. This includes core group operations (such as addition, scalar multiplication, identity, equality), as well as serialization and size-related properties.

To extend dlog-group with support for a new group backend, you need to implement the following traits:

• GroupScalar: Represents scalars from the field ${\mathbb{Z}}_n$. You must specify their size and how to generate a random scalar using a cryptographically secure rng (i.e., one implementing CryptoRng).

• GroupPoint: Represents elements of the group. This trait depends on GroupScalar and requires you to define the size of a point and implement scalar multiplication and point related operations.

• Group: The main trait that binds GroupPoint and GroupScalar together into a single group definition.

Once these are implemented, your group can be used interchangeably with existing ones like RistrettoGroup, P256Group, or others, benefiting from the abstraction provided by the library.

It is recommended to include proper testing within any module that introduces new functionality. Additionally, if comparing performance is of interest, you can add benchmarks in the file benches/group_bench.rs, at the end of the file you can find examples of how the benchmarking macros (which take advantage of the Group trait) are used.