MARA Holdings, a publicly traded Bitcoin miner, has removed the access-code requirement from Slipstream, its private transaction relay, offering Coldcard owners a way to move vulnerable funds without exposing their transfers to hackers first.
The company said in a Monday post on X that anyone could now submit a signed Bitcoin transaction without registering or installing client software.
MARA Holdings
- Unlike a normal transfer, which enters Bitcoin's public mempool, a shared waiting room for unconfirmed transactions, Slipstream sends it directly to MARA's private mempool.
- The Coinformer verified through the service's live API that its minimum submission fee was one satoshi per virtual byte at press time, although a transaction needed three to compete for inclusion in a block.
Moving before hackers notice
Peter Todd, a longtime Bitcoin Core developer whom a 2024 HBO documentary controversially suggested might be Bitcoin's pseudonymous creator, Satoshi Nakamoto, said in an X post that the service could help owners of certain 2-of-3 multisignature wallets, which require any two of three keys to authorize a transfer, when two keys were generated by compromised Coldcard devices but the third remains secure.
MARA Pool currently accounts for about 4.5% of recently mined Bitcoin blocks, according to data from Hashrate Index.
At that share, a simple statistical calculation puts the average wait for a MARA block at roughly 3.7 hours, assuming the fee is competitive, although mining luck can make it considerably shorter or longer.
- Broadcasting the rescue publicly may reveal enough wallet information for attackers controlling the other keys to create a competing transfer.
- Slipstream instead keeps it private until MARA mines it, meaning attackers may first see the transaction after it is confirmed.
The option arrives as Alex Thorn, research head at crypto firm Galaxy Digital, identified a likely fourth attack wave involving roughly 448 BTC and more than 700 potential victim addresses, which would bring the suspected total across four waves to roughly 1,815 BTC.