Google Multi-Party Compute Splits Crypto Keys for Banks, Launch Set for 2027

What happens to a bank's crypto if one person, one server or one cloud account gets compromised? Google thinks it has an answer. On October 28, the company said Google Multi-Party Compute, a custody security service for crypto and tokenized assets, is now in private preview for banks and other financial institutions, with a commercial launch planned for early 2027, according to CoinDesk.

Google planned to show the product at its first digital assets symposium in New York. Pricing has not been announced, and the banks testing it have not been named. Here is what the service does and what it leaves unsolved.

What is Google Multi-Party Compute?

It is a way to hold and move digital assets without ever keeping a complete private key in one place. Multi-party computation, or MPC, splits signing power into separate shares. Those shares work together to approve a transaction, but none of them alone can move funds.

Google says it had not offered a dedicated MPC custody product for crypto before. It did publish guidance in 2023 on building MPC systems with its Confidential Space technology, and it already sells Cloud Key Management Service and Cloud HSM for general key storage. The new product packages those ideas into something aimed squarely at financial institutions.

Alphabet is already using the system for its own digital assets on Ethereum and Solana, CoinDesk reported, though Google did not say which assets those are.

How does Google's key splitting actually work?

The setup has three moving parts.

1. Key shares in different places. A bank could keep one share in Google Cloud, one on its own hardware and one with a different cloud provider. That design means an outage or breach at a single provider should not be enough to sign a transaction.
2. A policy check before signing. Each transaction first passes through Google's Confidential Space, where a policy engine compares it with the institution's rules. Those rules can cover transfer limits, approved destination wallets and sign off from more than one department.
3. A signing threshold the customer picks. Institutions decide how many shares must agree, such as 2 of 3 or 5 of 7.

Google says customers keep control of their key material and that it cannot see the key in unencrypted form. At general availability the service will support ECDSA and Ed25519 signatures, the schemes used by Bitcoin, Ethereum, Solana and many other networks. Google also says the architecture can take a post quantum upgrade later without a redesign, but it has given no date for that.

Why is Google getting into crypto custody now?

Stolen keys remain the industry's most expensive weakness. CoinDesk cited Chainalysis data showing compromised private keys made up 43.8% of crypto stolen in 2024. DeFiLlama figures put cumulative losses from hacks and exploits at $16.69 billion as of June 2026, with roughly 40% of that tied to private key compromises.

This year supplied fresh examples. In March, an attacker took about $25 million from Resolv after combining a compromised key with weaknesses in its minting setup. In June, attackers drained more than $32 million from Humanity Protocol wallets after getting hold of a foundation member's keys.

Demand is also rising from the traditional side. Large banks keep edging into the asset class, from Deutsche Bank's custody plans to Schwab opening crypto trading to all clients. Rich Widmann, director of digital assets strategy at Google Cloud, told CoinDesk that "digital asset adoption and tokenization are at an inflection point."

Who is Google Multi-Party Compute built for?

Banks, asset managers and other regulated institutions that want to run their own custody business rather than hand assets to a crypto native firm. Google is pitching itself as neutral infrastructure: it supplies the signing and policy machinery, and the institution keeps the customer relationship.

That puts it up against specialists such as Fireblocks, Fordefi and BitGo, which already sell MPC custody to institutions, according to CoinDesk and TokenPost. Google's argument is that its existing banking relationships and security track record give it an edge. Whether banks want even more of their stack sitting with one cloud giant is a separate question they will have to weigh.

Individual crypto holders are not the audience. If you manage your own coins, the closer lessons are in stories like the Electrum fee bump theft and the Ngrave fake alert scam.

What can MPC custody not protect against?

Key splitting stops a thief who steals one share. It does not stop a legitimate employee who is tricked into approving a bad transfer. If the person with signing rights is fooled, the system will still sign.

Configuration matters just as much. A bank that sets loose transfer limits, or lets too many people change approval rules, weakens the protection on its own. And even with keys spread across providers, institutions still rely on Google for the software, the policy engine and day to day operations.

Then there are newer threats. Chainalysis found that scams linked to AI tools pulled in an average of $3.2 million per operation in 2025, against $719,000 for scams without that link, though the report does not prove AI caused the gap. Separately, Google researchers have estimated that a powerful enough quantum computer could work out a bitcoin private key from an exposed public key in roughly nine minutes. No such machine exists today, which is why the lack of a post quantum timeline is a gap rather than an emergency.

When can banks use Google Multi-Party Compute?

Right now only through the private preview, where unnamed design partners and large financial institutions are testing it. Google is aiming for commercial availability in early 2027. Rules for bank held crypto are also still settling, from the GENIUS Act stablecoin rule to new trust charters like Ripple's OCC approval.

The real test arrives when the first named bank goes live and tells customers its assets sit behind Google's key shares. More custody coverage lives on our crypto page.