Cardano Plutus Smart Contracts Verify Thousands of Signatures On-chain

The Cardano Foundation has announced that Plutus smart contracts can now verify thousands of signatures on-chain at low cost. This is thanks to the implementation of BLS12-381 elliptic curve cryptography, which allows for the aggregation of signatures.

BLS12-381 is a specific type of elliptic curve used in cryptography that has a useful property: it allows for the compression of multiple signatures into a single proof. This means that instead of verifying each signature individually, the contract can verify the entire batch at once, without affecting the on-chain cost.

The implementation is tied to Protocol Version 11, which is scheduled for rollout by May 2026 and will introduce five new Plutus built-in functions to support these operations. This upgrade builds on Cardano's existing support for ECDSA and Schnorr signatures, adding another cryptographic primitive to the toolkit available to developers building on Plutus.

For developers, this change is significant because it removes the need for off-chain verification, which introduces trust assumptions and can be vulnerable to attacks. By bringing verification fully on-chain, Cardano eliminates these dependencies and reduces the attack surface.