search

dedis / kyber

Advanced crypto library for the Go language
Other
640 stars 168 forks source link

Ristretto support #421

Open tucnak opened 4 years ago

tucnak commented 4 years ago

Hello,

As usual, many thanks for the most fantastic crypto construction Go library out there!

Are there any plans for Ristretto support? The group is ristretto255, which is built on top of Curve25519, so I assume this shouldn't be too hard to implement it in the current framework. Apparently, there are arguments in favour of using ristretto255, as opposed to ed25519, but I don't strictly understand what the benefits are. Am I right to assume that ristretto255 only uses 1/8 of the points, thus somehow eliminating the risk of malleability?

Cheers, Ian

ineiti commented 4 years ago

Hi Ian,

from what I know, there are currently no plans to do this. But if you want to give it a shot, I'm sure it would be accepted as a PR ;)

The *25519 groups in this library per default also only use 1/8 of the available points (and scalars), which is parametrizable using the subgroup parameter: https://github.com/dedis/kyber/blob/cf1d7f3a955c4dff40bf5b1b27576ea9713569a8/group/curve25519/suite.go#L59