Key facts
- Blockstream said the system runs the entire signing protocol inside Thales hardware security modules.
- Back said conventional MPC protocols are too complex and interactive for fully offline cold storage.
- Back cited the Binance $6.3 billion hack, in which attackers obtained credentials to wallet-signing infrastructure.
- Back said AI could help attackers find small implementation errors in complex MPC systems.
Blockstream, the Bitcoin infrastructure company led by Adam Back, announced a custody system for institutional digital assets on November 13, 2026, developed with French technology group Thales, according to Cointelegraph.
The system combines Thales hardware security modules, dedicated devices that hold cryptographic keys, with Blockstream's Secure Multi-Party Computation technology, the company said. Blockstream said the entire signing protocol runs inside the protected environment of the Thales modules, unlike conventional MPC setups that may perform parts of the signing process outside dedicated security hardware.
Back told Cointelegraph that conventional MPC protocols are too complex and too interactive for fully offline cold storage. "When people talk about MPC, they're talking about some very esoteric and complicated protocols that are hard to secure and are very interactive," he said.
Back cited the Binance $6.3 billion hack as an example of the risk in internet-connected custody. According to Binance's investigation, attackers compromised employee devices and obtained credentials that allowed access to the exchange's wallet-signing infrastructure. Back also said AI could help attackers find small implementation errors in complex MPC systems, and urged institutions to move assets into cold storage.