TODO: Add a basic Readme

[c0gent]

@vkomenda I've been told you may already be handling this or at least you have an example you want to use already but I'm happy to help if you can show me which example you want to use.

Or I'll just make something up :P

[andogro]

Basic README outline - will hinge on nature of the example.

Description

Threshold Crypto provides constructors for encrypted message handling within a public key encryption system. We utilize the pairing elliptic curve library to create and enable reconstruction of public and private key shares.

In a network environment, messages are signed and encrypted, and key and signature shares are distributed to network participants. A message can be decrypted and authenticated only with cooperation from any subset of threshold + 1 network participants.

Installation / Usage

• Parameters, parameter generation
  • threshold, signatures, message?
• Example Use Case

Testing

License

Contributing

[c0gent]

I was going to make a pretty standard Rust library readme with the usual sections, something I've done many times (https://github.com/cogciprocate/ocl, https://github.com/cogciprocate/voodoo, etc.).

I'll certainly consult you for approval before merging it @andogro :)

[c0gent]

I'll be sure to copy CONTRIBUTING into the repo and add a link, etc.

[andogro]

sure, let me know how I can help as needed.

[c0gent]

Will do, I'll sumbit a PR for it as soon as we figure out what example we want to use.

[c0gent]

I hope I'm not stepping on your toes here by the way. If you have it under control just wave me off. I'm not used to having a dedicated writer available! :)

[afck]

I'd probably put the introductory text like this:

This is a threshold cryptosystem for collaborative decryption and signatures: Choose a threshold value t, create a key set, distribute N secret key shares among the participants and publish the public master key. A third party can now encrypt a message to the public master key, and any set of t + 1 participants—but no fewer!—can collaborate to decrypt it. Also, any t + 1 participants can collaborate to sign a message, producing a signature that can be verified against the public master key.

One application is distributed networks that need to tolerate up to t adversarial nodes: It requires t + 1 nodes to reveal information encrypted to the network (the master key), or to produce information signed by the network, so it can be trusted by a third party.

This cryptosystem has the property that signatures are unique, i.e. independent of which particular participants produced it. If S1 and S2 are signatures for the same message, produced by two different sets of t + 1 secret key share holders each, then they won't just both be valid, but in fact equal. This is useful in some applications, for example it allows using the signature of a message as a pseudorandom number that is unknown to anyone until t + 1 participants agree to reveal it.

In its simplest form, threshold cryptography requires a trusted dealer who produces the secret key shares and distributes them. However, there are ways to produce the keys themselves in a way that guarantees that nobody except the corresponding participant knows their secret in the end, and this crate includes the basic tools to implement such a Distributed Key Generation scheme.

[afck]

For usage examples, maybe some of the tests could be adapted:

• test_simple_sig, test_threshold_sig for signing.
• test_simple_enc, test_threshold_enc for encrypting and decrypting.
• poly::distributed_key_generation for distributed key generation.