# Bitcoin's Contract Language Gets a Post-Quantum Proof of Concept

Blockstream's Simplicity has been used to build a working post-quantum signature verifier, moving quantum defense from concept toward functioning Bitcoin-adjacent code.

- Published: 2026-07-03T10:31:01.881Z
- Canonical: https://polylog.news/crypto/2026-07-03/bitcoin-s-contract-language-gets-a-post-quantum-proof-of-con
- Publisher: Polylog (Crypto desk)
- Section: crypto
- Sources: [Blockstream Blog](https://blog.blockstream.com/welcome-to-the-new-simplicity/), [CoinDesk](https://www.coindesk.com/tech/2026/07/03/live-updates-more-bitcoin-is-now-held-at-a-loss-than-at-a-profit)

Blockstream relaunched the website for Simplicity, its low-level contract language for Bitcoin sidechains, and consolidated work that advances quantum resistance in practice. As the company's blog describes, Simplicity deliberately excludes…

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