Google Cloud detailed a service that lets banks and other financial institutions jointly sign bitcoin transactions, the company said as it opened a digital-assets security symposium in New York on Wednesday.
The tool, called Google Multi-Party Compute, splits a private key into fragments held by separate parties, so no single participant controls the full key. Before signing, the system checks the transaction amount and the type of destination address and flags change outputs.
It supports the ECDSA and Ed25519 signing algorithms and is built to allow a future shift to post-quantum cryptography, according to Google Cloud's documentation.
“Digital asset adoption and tokenization are at an inflection point. As regulated financial institutions begin adopting blockchains, tokenization, they need scalable, proven infrastructure to secure their clients' assets,” Rich Widmann, Google Cloud's director of digital assets strategy, wrote in the company's materials.
Google Cloud pointed to the rising cost of private-key theft to explain the launch. Chainalysis found that compromised keys were behind 43.8% of all cryptocurrency stolen in 2024, and that AI-tool-linked scams took in $3.2 million on average per case in 2025, versus just $719,000 when no such tools were involved.
DeFiLlama figures show blockchain projects had racked up a combined $16.69 billion in losses from hacks and exploits by June 2026, with roughly 40% of that stemming from private-key compromises.
The service is currently in private preview, with several design partners and financial institutions testing it; Google Cloud has not named them. The company plans to make it commercially available in early 2027 and has not disclosed pricing.
Google Cloud's documentation also cites earlier research estimating that a powerful future quantum computer could derive a bitcoin private key from an exposed public key in about nine minutes, risking up to 6.9 million bitcoin. The new architecture aims to address that scenario with post-quantum algorithms.
