Ethereum's Quantum Upgrade Countdown Begins: 2029 Target Under Pressure

Ethereum is racing to complete its transition to a quantum-resistant Layer 1 network by the end of 2029. This move aims to safeguard against the threat of quantum computers, which could potentially compromise the security of traditional public-key cryptography used in digital signatures.

The development team has planned for an intermediate step beginning at the end of 2026, where account signatures will transition to stronger ones without requiring a full network switch. This upgrade will be followed by five further updates after Glamsterdam, giving developers around seven months between each milestone.

As part of this effort, Ethereum is also working on leanXMSS signatures, which provide similar security against quantum computing attacks but come with the drawback of significantly increased size, approximately 3100 bytes. To mitigate this issue, a new system called leanVM is being developed to reduce these signatures by around 250 times.

Another approach proposed in EIP-8141 would allow individual accounts to choose whether to use safer signature options, rather than implementing a network-wide change. The team will need to balance security with the potential costs and performance impact of these changes.