Blockstream Publishes BIP for Quantum-Secure Bitcoin via SHRINCS
Blockstream has published a Bitcoin Improvement Proposal (BIP) for its experimental post-quantum signature scheme, SHRINCS. This development is significant because it addresses the vulnerability of Bitcoin's current elliptic-curve signature system to quantum threats.
The BIP positions SHRINCS as an actionable candidate for Bitcoin's post-quantum signature upgrade path. It aims to reduce on-chain size by shrinking the signature payload itself, rather than relying on external aggregation methods like zero-knowledge proof aggregation.
SHRINCS is designed to be 'Bitcoin-native' and smaller than many NIST-aligned post-quantum signature alternatives. However, it comes with trade-offs, including operational fragility, as it behaves in a stateful way, which can reduce on-chain size but introduces wallet/device recovery and interoperability risks.
Blockstream's research has explored complementary ideas, such as signature-size reduction and potential ZK proof aggregation, while keeping governance and deployment decisions separate. The company has also demonstrated SHRINCS running on common hardware wallets and introduced a companion backup/derivation concept called 'SHRIMPS' to support signing by backup devices initialized from the same seed.