Google Cloud puts its Multi-Party Compute crypto custody service into private preview for banks

Google Cloud has put a new crypto custody and signing service into private preview, aimed at banks and other financial institutions that want to hold and move cryptocurrencies and tokenised assets. The product, called Google Multi-Party Compute (MPC), was unveiled around Google’s digital assets symposium in New York on Wednesday 28 October.

Google plans to make the service commercially available in early 2027. It has not announced pricing.

Google said several design partners and financial institutions are already testing the service, but it did not name them. It also said Alphabet, Google’s parent company, has begun using the technology to secure its own digital assets on the Ethereum and Solana blockchains, without saying which assets are involved.

How it works. Instead of keeping a wallet’s private key in a single place, the service splits it into separate shares so that no one machine ever holds the whole key. Google gave the example of a bank that keeps one share in Google Cloud, a second on its own hardware and a third with another cloud provider.

When the bank wants to move funds, the transaction is sent to Google’s Confidential Space, a hardware-isolated computing environment. A policy engine there checks the transfer against the institution’s rules before any signing begins. Those rules can include caps on the amount, a list of approved destination wallets and sign-off from several departments.

Customers can also set how many share-holders must take part in a signature, such as two of three or five of seven. Google said the service supports key recovery, and that customers keep control of their key material: the company says it cannot see it in unencrypted form, even for shares held on its own infrastructure.

Where it fits. Google already sells key-management tools such as Cloud KMS and Cloud HSM. It said it has not previously offered a dedicated MPC product for crypto custody, and that the new service packages MPC signing, transaction policies and key recovery so that customers do not have to assemble them themselves.

The service will compete with specialist providers including Fireblocks, Fordefi and BitGo. Google is pitching itself as a neutral infrastructure supplier for banks that would rather not depend on a vendor that also competes for their customers.

Limits. Google said the current protections are aimed at problems such as stolen credentials and unauthorised transactions. They do not address a bank’s own staff being tricked into approving a malicious transfer, and the security of any deployment still depends on how the institution configures it and who is allowed to change its approval rules. Google also did not provide independently verified speed comparisons with existing custody products.

On quantum computing, Google said the design should allow a later move to post-quantum signatures without customers having to rebuild their systems. It gave no timetable. At launch the service is meant to support the ECDSA and Ed25519 signature schemes used by networks such as Bitcoin, Ethereum and Solana.

“Digital asset adoption and tokenization are at an inflection point,” Rich Widmann, Google Cloud’s director of digital assets strategy, said. He said regulated institutions moving onto blockchains “need scalable, proven infrastructure to secure their clients’ assets.”