Google Cloud Enters Crypto Custody With MPC Key-Splitting Service

Google Cloud unveiled a Multi-Party Compute (MPC) service on October 28, 2026, at its first digital assets symposium in New York City, entering the institutional crypto custody market and placing it in direct competition with Fireblocks and BitGo. The service is in private preview, with general availability expected in early 2027.

The product attacks one of crypto's oldest operational risks: a single private key that, if leaked, exposes everything it protects. Under Google's design, every key is split into multiple shares distributed across separate environments. Some fragments can sit on a customer's on-premises hardware, others inside Google Cloud, and still others with entirely different cloud providers. Those shares cooperate to sign transactions without the complete key ever being reassembled in one place.

How the threshold schemes work

Google supports threshold configurations including 2-of-3 and 5-of-7. In a 2-of-3 setup, any two of three key shares can authorize a transaction; a 5-of-7 arrangement requires five of seven shares to agree. The practical consequence: an attacker must compromise several independent systems simultaneously, not just one. A single breached environment is no longer sufficient to move assets.

A policy engine embedded in Google's Confidential Space adds a governance layer before any signing occurs. It enforces rules such as spending limits and approved recipient lists.

The trust question is unavoidable for a hyperscaler handling key material. Google states it has no plaintext access to the key shares it helps manage. The multi-cloud design reinforces that position — customers are not forced to place every share in Google's infrastructure, which lowers the switching and concentration risk that a single-vendor arrangement would carry.

Who is it for, and who is already using it?

This is not a retail wallet. The service targets institutional clients, with banks as a particular focus, and use cases centered on safeguarding and transferring digital and tokenized assets. A select group of design partners and major financial institutions currently has access.

Alphabet, Google's parent company, already runs the system in production to protect its own assets on the Ethereum and Solana blockchains — an internal validation that practitioners will read as a meaningful reference before wider rollout.

What does this change for the custody market?

For Fireblocks and BitGo, specialists that built businesses around institutional digital asset security, the competitive calculus shifts. Google Cloud arrives with deep enterprise relationships, an existing cloud footprint inside many banks, and boardroom brand recognition. A bank that already runs workloads on Google Cloud can now evaluate custody-grade key management from an incumbent vendor rather than onboarding a specialist.

The incumbents retain years of operating history in this niche. Google has scale. Which advantage weighs more depends on how institutions price operational maturity against integration convenience.

Three developments will define the next phase: the general availability timeline in early 2027, which financial institutions publicly sign on beyond the unnamed design partners, and how Fireblocks and BitGo respond on pricing, features, or partnerships. Until GA, Google's private preview cohort will effectively serve as the market's first read on whether hyperscale custody displaces specialist infrastructure.