Cardano development company IOHK issued a document saying that in order to facilitate developers to build cross-chain applications, Input Output Global (IOG) added new built-in functions to Plutus to support ECDSA and Schnorr signature algorithms, allowing developers to use a wider range of multi-signatures in Cardano and threshold signature design. Cardano uses the elliptic curve Curve25519 as the base curve (aka Ed25519), not ECDSA and Schnorr. Therefore, cross-chain DApp development can be done more securely only if ECDSA and Schnorr are also provided as built-in functions of Plutus. IOHK also stated that based on community votes, the mainnet upgrade is tentatively scheduled for 05:44:51 on February 15, 2023, Beijing time. On this basis, IOG plans to update the pre-production testing environment at 08:00:00 on February 11, 2023, Beijing time.