Google is previewing Google Multi-Party Compute, a crypto custody system that splits private signing keys across separate environments, with several financial institutions testing it ahead of a planned early 2027 launch. The company announced the product on October 28, 2026, at a digital assets symposium in New York.
The system divides a signing key into fragments held by separate parties or machines. A transaction requires a threshold number of fragments to authorize, and the full key is never assembled in one place. A bank could hold one share on its own hardware, another in Google Cloud, and a third with a rival cloud provider. Institutions can configure thresholds such as two-of-three or five-of-seven.
Before any signature, a policy engine running inside Google’s Confidential Space checks the transfer against limits, destination restrictions, and approval rules. “Google says it has no access to key shares in unencrypted form,” according to CoinDesk reporting.
Private Preview and Commercial Timeline
Google Multi-Party Compute is in private preview with several financial institutions. Alphabet, Google’s parent company, has begun using the system to secure its own assets. Commercial availability is planned for early 2027, though pricing has not been disclosed.
Google positions itself as a neutral supplier for banks that do not want to rely on competitors. Banks already use specialized platforms such as BNP Paribas’s custody work with Metaco and multi-institution vaults built with BitGo. Fireblocks and Fordefi also operate in the institutional custody space.
Key Vulnerability: Compromised Private Keys
The product addresses a material security gap. Chainalysis data shows that 43.8 percent of cryptocurrency stolen in 2024 was attributed to compromised private keys. Through June 2026, 40 percent of the $16.69 billion lost to hacks came from key compromises, according to DeFiLlama.
In June 2026, an attacker took seven keys from one developer’s computer during the Humanity Protocol breach and drained wallets across two networks. Multi-party computation prevents a single compromised machine from exposing the full signing key.
Quantum Computing and Post-Quantum Readiness
Google researchers estimate that a sufficiently powerful quantum computer could derive a bitcoin private key from an exposed public key in nine minutes. Approximately 6.9 million bitcoin have exposed public keys, creating a theoretical long-term risk.
“Google says its architecture can adopt post-quantum signatures later without forcing institutions to rebuild their systems,” according to CoinDesk. No timetable has been set for post-quantum signature adoption.
AI and Scam Losses
Chainalysis data from 2025 shows that AI-linked scam operations averaged $3.2 million per operation, compared to $719,000 for non-AI scams. However, the data links the two figures but does not prove that AI caused the difference. Justin Drake, an Ethereum researcher, warned that AI could find mathematical shortcuts weakening wallet signatures, but no AI system has shown that capability.
