Google previews MPC crypto custody service for banks

Key points

• Google Multi-Party Compute is in private preview with several unnamed financial institutions
• Commercial availability is planned for early 2027; pricing has not been disclosed
• Alphabet uses it to secure its own assets on Ethereum and Solana, per CoinDesk
• Private keys split across systems; a policy engine checks transfers before signing

Google is previewing a crypto custody and security service called Google Multi-Party Compute, which is being tested by several unnamed financial institutions, CoinDesk reported on Wednesday. The product is in private preview, and Google plans to make it commercially available in early 2027. Pricing has not been disclosed.

The company showed the system at its first digital assets symposium in New York. According to CoinDesk, parent company Alphabet is already using the service to secure its own digital assets on Ethereum and Solana, though Google did not say which assets.

How Google’s split-key custody works

The service relies on multi-party computation, or MPC. Instead of storing a private key in one place, the system divides it into fragments held on separate machines or by separate parties, and a set number of fragments must cooperate to sign a transaction. The full key is never assembled in one location.

CoinDesk gave an example in which a bank keeps one share in Google Cloud, a second on its own hardware and a third with another cloud provider. Signing thresholds, such as two of three or five of seven, are configurable.

Before any signature is produced, a policy engine running in Google’s Confidential Space checks the transaction against institutional rules. Those can include amount limits, restrictions on destination addresses and approvals from multiple departments. Google says customers keep control of their key material and that the company cannot access it in unencrypted form.

At general availability the service is expected to support the ECDSA and Ed25519 signature schemes. Google says it could add post-quantum cryptography later without forcing institutions to redesign their systems, but it has not given a timetable.

Cointelegraph, in its own report, said Google’s documentation positions the preview for institutional Bitcoin custody. It said the documentation describes the service as provided “as is, with potentially limited support,” and that release notes show Google expanding Bitcoin security rules on Oct. 1 to evaluate transaction amounts, destination address types and change outputs. Speakers listed for the symposium came from Morgan Stanley, OKX, Citi and Wells Fargo, according to Cointelegraph. Google did not respond to its questions about availability by publication.

The key-theft problem behind the product

CoinDesk cited Chainalysis data showing compromised private keys accounted for 43.8% of cryptocurrency stolen in 2024. It also cited DeFiLlama figures showing blockchain projects had lost a cumulative $16.69 billion to hacks and exploits as of June 2026, with roughly 40% tied to private-key compromises.

Recent cases include a March 2026 attack on stablecoin protocol Resolv, in which a compromised privileged key helped a hacker extract about $25 million, and a June breach of Humanity Protocol, where attackers drained more than $32 million from at least 17 wallets after compromising a foundation member’s keys, according to CoinDesk.

The report also pointed to concerns about artificial intelligence. Chainalysis found that scams linked to AI-tool vendors averaged $3.2 million per operation in 2025, compared with $719,000 for those without such links, though the data does not establish that AI caused the difference. Ethereum researcher Justin Drake has warned that AI advances could eventually weaken wallet signatures, but no AI system has demonstrated that ability, CoinDesk noted. Google researchers have separately estimated that a future quantum computer could derive a bitcoin private key from an exposed public key in about nine minutes, with roughly 6.9 million bitcoin having exposed public keys.

Rich Widmann, Google Cloud’s director of digital assets strategy, said that “digital asset adoption and tokenization are at an inflection point,” per CoinDesk.

Competition and open questions

Google enters a market where Fireblocks, Fordefi and BitGo are established providers. Bitcoin Magazine reported that Google is pitching itself as a neutral infrastructure supplier for banks that do not want to depend on competitors, citing its banking relationships and security expertise.

Questions remain. Google has not named the participating institutions or the assets Alphabet secures with the system. CoinDesk noted that banks could still rely on Google for parts of the software, policies and operations, and that real-world security will depend on how each institution configures the system.