Thread by @crypto_cream_

One thing people often don't know about #Ergo is it's use of Sigma Protocols (Σ-protocols) (afaik entirely unique to Ergo) and will dive into them in this thread 👇👇

1/ #Ergo’s smart contracts and #DeFi functionality are built on Sigma protocols – a powerful, flexible class of zero-knowledge proofs. A zero-knowledge proof allows someone to prove they know the solution to a problem without actually revealing the solution itself $ERG

2/ ∑-protocols are a sub-class of efficient and composable proof-of-knowledge protocols, using simple AND and OR logic, you can ask for a signature with "Prove to me knowledge of either this secret OR that secret" (this is a one-of-two ring signature) $ERG #privacy

3/ Or you can ask, "Prove to me knowledge of any two of these three secrets" (a two-of-three ring signature). Those are just two simple examples, they can be far more complex and sophisticated for even greater #security and #privacy $ERG

4/ When combined with a #blockchain, these composable proofs enable some very powerful use cases, including conditions based on blockchain state.
For example, "If the deadline block height has been reached, Alice can provide knowledge of a secret key for a refund..

5/ ..OR a ring signature from Alice and Bob is required to spend coins." Or "If this account holds a minimum of 100 ERG, Alice OR Bob can remove funds above that amount." with many more use cases for powerful #DeFi applications

6/ In comparison with zk-SNARKs:
- ∑ don’t require a Trusted Setup
- ∑ use only a very simple and well tested cryptographic assumption
- ∑ are comparatively much easier to understand and implement
- ∑ can be extremely fast for proof generation and verification
$ERG #DeFi