Cross-Input signature aggregation first!
Discussion
Bike shedding must end
1. It's bad for privacy
2. Don't need to wait for other proposals to discuss covenants
1. Every change in code can bring new risks and challenges. CISA just allows us to ONLY provide a single signature per #Bitcoin transaction even when there are multiple inputs. In this way we can at least reduce the transaction size and enhance privacy by making it harder to distinguish between different inputs in a transaction. When multiple inputs are aggregated into a single signature, it becomes less clear which inputs belong to which users, thereby obscuring the transaction history.
This could also make CoinJoin transactions, which often involve multiple inputs, more cost-effective compared to traditional transactions, driving more privacy benefits for less technical Bitcoin users.
2. That's true. But I personally would like to see the scaling and privacy improvements that can be achieved with Taproot, Schnorr and signature aggregation before messing with anything else.
CISA does not improve privacy. It only aggregates signatures for inputs.
Coinjoin is already super cheap at 1 sat/vbyte although nobody cares. There isn't enough volume.
Covenants will use taproot and schnorr. They are more researched than CISA.