crypto-bigint

[tarcieri]

Hello!

I thought you might be interested in the crypto-bigint crate we've been working on as part of RustCrypto, which we are slowly beginning to use in our elliptic curve crates:

• https://crates.io/crates/crypto-bigint
• https://docs.rs/crypto-bigint

We're targeting Rust 1.51+ with it and aggressively trying to leverage both const generics and const fn as much as is possible on stable Rust.

We're targeting constant-time operation by default, with some secondary variable-time implementations explicitly called out as *_vartime.

I'm not sure we yet provide the functionality you need, or if the approach we're using (fixed-width, stack-allocated, no_std friendly big integers) actually maps well to this particular problem, but I thought I'd give it a mention.

If there's missing functionality you'd like to see implemented first, that's definitely something we'd like to know about:

https://github.com/RustCrypto/utils/issues/453

[mikelodder7]

Cool, thanks for the heads up. I'll check it out. The first I notice is I need the ability to represent negative numbers which often affects how computations happen in groups of unknown order.

[mikelodder7]

Crypto-bigint will be a nice addition for going to no-std environments and constant-time operations. Let me know how I can help.

[davfra]

What is the current status on this?
Can you guesstimate the effort and/or steps needed to include crypto-bigint in unknown_order or comment on the obstacles?

[mikelodder7]

There’s some methods missing from crypto-bigint I’m working to add then it will be quick

[davfra]

Cool! Is there anything specific I could help with?

[mikelodder7]

You stub it in for now and implement what can be done

[donkey-donkey]

hi, wondering if this will help with some of the no_std. trying to use this unknown_order presently and getting a std error from num-traits

[mikelodder7]

I'm actually close to having crypto-bigint almost integrated. Expect it within a week or two

[donkey-donkey]

rad. super stoked on your timing. thanks

[donkey-donkey]

rad. super stoked on your timing. thanks

[donkey-donkey]

checking in on this to see if there is anything that we can test? thanks

[mikelodder7]

Just finishing some testing. I'll push what I have. Also doing some code cleanup

[donkey-donkey]

awesome stoked to try it out.
thanks.

[mikelodder7]

Sorry I'm slow on this. Been traveling a ton and had zero time. Just a minor issue with serialization then I think I've got it

[mikelodder7]

Published an RC candidate `unknown_order = "0.7.0-rc0". The one issue I'm having is when you try to serialize to json or toml or anything human readable I get

serializer is human readable, which requires the alloc crate feature.

Have you ever seen this @tarcieri with crypto-bigint?

[donkey-donkey]

hi. any updates. i noticed the repo is now with hyperledger. are you still working on it? thanks much.

[mikelodder7]

Yes I've just been really busy. Take a look and see if you can figure out why the serialize bug happens. That's the only hinderance right now.

[mikelodder7]

Addressed in #9