MARA opens Slipstream to public as Coldcard wallet losses rise

The browser-based Bitcoin transaction tool lets users submit signed transfers directly to MARA's mining pool, bypassing the public mempool as thefts tied to a Coldcard seed-phrase flaw reach 1,816 BTC.

BTC

Summary

MARA Holdings has opened its Slipstream Bitcoin transaction service to the public at no additional charge beyond normal network fees, allowing users to submit signed transactions directly to MARA's mining pool through slipstream.mara.com without client software or a client code requirement. By bypassing the public mempool, the service is designed to reduce front-running and information leakage, a security benefit that is particularly relevant for multisig and Coldcard wallet users trying to move funds after a seed-phrase flaw disclosed at the end of July. Researchers traced the Coldcard issue to a March 2021 firmware coding error that reduced effective randomness for some 24-word seed phrases, and theft estimates had climbed to 1,816 BTC worth about $116 million from more than 5,200 wallets as of Aug. 4. MARA said users should pay competitive Bitcoin fees, with a minimum submission rate of the greater of 1 sat/vByte or the current mempool priority rate, while confirmation still depends on MARA finding a block.

Terms & Concepts
  • mempool: Bitcoin's public waiting area for unconfirmed transactions, where pending transfers can be seen before they are included in a block.
  • multisig: A wallet setup that requires multiple signatures or keys to authorize a transaction.
  • Replace-by-Fee: A Bitcoin fee-bumping mechanism that lets a user replace an unconfirmed transaction with a higher-fee version.