More than three dozen bitcoin and crypto companies have asked the largest AI labs to give open-source security researchers early access to their most capable models, arguing that the people defending a trillion dollars of infrastructure are working with weaker tools than those attacking it.

The letter, organised by the Bitcoin Policy Institute and published earlier this week, is signed by Coinbase, Block, BitGo, Blockstream, Anchorage Digital, ARK Invest, Bitwise, Foundry, Casa, Exodus and others, alongside nonprofit developer funds including Brink, Chaincode and Btrust.

Its central complaint is that Bitcoin Core developers, the small group maintaining the software that runs the network, cannot access the programs’ labs run for trusted…