Midnight, a data protection-focused blockchain operating in the Cardano ecosystem, has upgraded its mainnet from Ledger 8 to Ledger 9, a hard fork that introduces new cryptographic support and smart contract improvements. According to Midnight's release announcement, the upgrade adds ECDSA and Keccak-256 compatibility, contract-to-contract execution, and custody support, improving compatibility with existing blockchain and custody infrastructure. Unlike previous upgrades, the team deployed Ledger 9 directly to mainnet, bypassing the network's standard Preprod testing and soak period.

Ledger 9 Adds Cryptographic and Custody Support

The release introduces native ECDSA and Keccak-256 support, standards that allow developers to build connections with existing blockchain infrastructure, including Bitcoin and Ethereum. ECDSA is the signature scheme that has secured Bitcoin and Ethereum since their launch, while Keccak-256 serves as Ethereum's core hash function, meaning signing and hashing infrastructure built around those standards can now interact with Midnight. The ledger also accepts both Schnorr and ECDSA signatures for transaction authorization.

In addition, BIP-44 address derivation support—the hierarchical deterministic wallet standard widely implemented across consumer wallets and institutional custody software—allows wallet providers and institutional custodians to keep using their existing software. According to the announcement, these capabilities support asset transfers between networks and integrations with custody providers, and developers can also build applications involving stablecoins and private financial transactions.

Smart Contracts Gain Direct Execution Capabilities

Ledger 9 also introduces contract-to-contract execution, allowing smart contracts to call other contracts within a single transaction. Composable calls of this kind have long been a baseline capability of established smart contract platforms such as Ethereum, and their arrival gives Midnight developers access to the multi-step workflow patterns those ecosystems are built around. As a result, developers can combine operations such as token approvals, swaps, and deposits into one user action.

Contracts can now identify which other contract initiated a call, allowing applications to restrict sensitive operations to approved contracts. Smart contracts can additionally publish events and logs after transactions finalize, and wallets, explorers, and tracking applications can use these updates to refresh information. Together, these changes enable more complex operations to be carried out in a single transaction.

The upgrade also moves zero-knowledge proofs and verification keys to Zero-Knowledge Intermediate Representation V3, updating the cryptographic layer that underpins Midnight's data protection features. Performance improvements and security patches accompany the release.

Developers Must Update Tools After Mainnet Upgrade

Existing balances and deployed smart contracts migrated automatically during the upgrade. Developers, however, must update their applications to Midnight.js 5. Undeployed contracts also require compilation through the updated Compact toolchain targeting Ledger 9.

Mainnet cNIGHT holders do not need to register again for DUST generation, the process by which holding NIGHT produces DUST, the renewable resource that funds activity on the network. Developers using Preview and Preprod, however, must re-register their tNIGHT to resume DUST generation.

Midnight said documentation covering the newer features will arrive over the coming weeks. The team deployed Ledger 9 directly to mainnet because security fixes required a more controlled release path, a decision that bypassed the usual Preprod deployment and soak period.