Silent Shard uses Multiparty computation (MPC) and enables a set of parties that do not trust each other to jointly compute a secret signing key without being constructed in one place and an ECDSA signature over their secret key shards while not sharing them with any of the involved parties, removing single points of trust.
TSS consists of three stages:
These functions involve cryptographic computing at the participating nodes of the MPC quorum and exchanges of rounds of messages which ultimately lead to the generation of a valid signature at the requested node. These computing nodes can be any device with sufficient computational and memory capability, including but not limited to smartphones, server nodes, and edge devices. The basic philosophy behind Silent Shard remains that no single device holding the private key can be used to generate signatures and move digital assets. The private key is shared among multiple computing nodes so that no party has any information about the key. Then, in order to generate a signature, the threshold number of devices run a secure two-party computation protocol that generates the signature without revealing anything about the parties' key shares to each other. These devices may or may not be associated with the same person or organization and can be any form factor. Thus, one could use this to create a wallet, sharing the private key between one's mobile and one's laptop, between one's mobile and a VM in the cloud, and so on.
The library contains a small set of tests. Please look for usual Rust tests in src/dkg.rs and src/dsg.rs
Distributed Key Generation
cargo test dkg::dkg2_out_of_2// 2 parties and t=2
cargo test dkg::dkg2_out_of_3// 3 parties and t=2
Distributed Signatures:
cargo test dsg::sign_2_out_of_2
cargo test dsg::sign_2_out_of_3
Compute presignature only:
Run the dsg::sign_2_out_of_* without the last round:
let mut rng = rand::thread_rng(); let chain_path = DerivationPath::from_str("m").unwrap(); let mut parties = dkg(ranks, t) .into_iter() .take(t as usize) .map(|s| State::new(&mut rng, s, &chainpath).unwrap()) .collect::<Vec<>>();
let msg1: Vec<SignMsg1> =
parties.iter_mut().map(|p| p.generate_msg1()).collect();
check_serde(&msg1);
let msg2 = parties.iter_mut().fold(vec![], |mut msg2, party| {
let batch: Vec<SignMsg1> = msg1
.iter()
.filter(|msg| msg.from_id != party.keyshare.party_id)
.cloned()
.collect();
msg2.extend(party.handle_msg1(&mut rng, batch).unwrap());
msg2
});
check_serde(&msg2);
let msg3 = parties.iter_mut().fold(vec![], |mut msg3, party| {
let batch: Vec<SignMsg2> = msg2
.iter()
.filter(|msg| msg.from_id != party.keyshare.party_id)
.cloned()
.collect();
msg3.extend(party.handle_msg2(&mut rng, batch).unwrap());
msg3
});
check_serde(&msg3);
let pre_signs = parties
.iter_mut()
.map(|party| {
let batch: Vec<SignMsg3> = msg3
.iter()
.filter(|msg| msg.from_id != party.keyshare.party_id)
.cloned()
.collect();
party.handle_msg3(batch).unwrap()
})
.collect::<Vec<_>>();
check_serde(&pre_signs);
let hash = [255; 32];
let (partials, msg4): (Vec<_>, Vec<_>) = pre_signs
.into_iter()
.map(|pre| create_partial_signature(pre, hash))
.unzip();WASM bindings for dkls23-ll.
Install wasm-pack:
curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
wasm-pack build -t web wrapper/wasm-llTo run the test install deno:
curl -fsSL https://deno.land/install.sh | sh
deno test -A wrapper/wasm-ll/tests/tests.ts