# A live OP Stack rollup replaces signatures with hash chains as Aztec sets a 2030 post-quantum deadline

The bb84 chain has run on Ethereum mainnet since Sept. 30 with no elliptic-curve signatures inside the layer-2, while Aztec says full migration will also require changes to Ethereum's own data layer.

- Published: 2026-10-25T05:49:12.746Z
- Canonical: https://polylog.news/crypto/2026-10-25/a-live-op-stack-rollup-replaces-signatures-with-hash-chains
- Publisher: Polylog (Crypto desk)
- Section: crypto
- Sources: [Ethereum Research](https://ethresear.ch/t/a-hash-only-rollup-op-stack-l2-accounts-as-lamport-style-hash-chains-no-ecdsa-inside-the-l2/26172), [Aztec Network](https://aztec.network/blog/post-quantum-aztec), [The Defiant](https://thedefiant.io/news/blockchains/aztec-targets-full-post-quantum-migration-by-end-of-2030), [Crypto Times](https://www.cryptotimes.io/2026/10/16/aztec-sets-2030-target-for-full-post-quantum-blockchain-migration/)

The founder of bb84, a payments app, described on the Ethereum Research forum an OP Stack rollup on Ethereum mainnet whose transactions carry no signatures at all. The chain has chain ID 42069000 and has run since Sept. 30. Accounts are bui…

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