256 Foundation has launched its 256 Red Team security effort to audit ASIC miner firmware, according to a post shared by Bitcoin News on X. The group said it used reverse engineering, live traffic capture, and share-level reconciliation in its review process. The team reported that it has filed 41 issue reports covering stock Bitmain firmware as well as third-party options including LuxOS, VNISH, and Braiins OS. The issues identified include unauthenticated factory APIs, paths that can grant root access, default credentials, embedded vendor SSH keys, and update tools that cannot verify what is being installed. After decompiling Bitmain miner daemons and examining live connections, the researchers said they found no evidence of hashpower skimming, remote kill switches, or covert beacons in Bitmain’s stock firmware. They said the main concerns were concentrated in third-party “optimization” firmware instead. The researchers have sent three responsible disclosures to VNISH, Luxor, and Braiins, giving each party 30 days to respond before public disclosure. Future audits are planned for MicroBT, Canaan, Auradine, Bitdeer, and ePIC.

Bitcoin News said in a post on X that 256 Foundation has launched the 256 Red Team, a security effort focused on auditing ASIC miner firmware. The project uses reverse engineering, live traffic capture, and share-level reconciliation to inspect firmware behavior. According to the team, it has filed 41 issue reports covering Bitmain’s stock firmware as well as third-party options including LuxOS, VNISH, and Braiins OS. Reported findings include unauthenticated factory APIs, paths that can lead to root access, default credentials, embedded vendor SSH keys, and update mechanisms that cannot verify what is being installed. After decompiling Bitmain’s miner daemon and reviewing live connections, researchers said they found no evidence in Bitmain’s original firmware of hashrate skimming, a remote kill switch, or covert beacons. They said the main risks were concentrated in third-party “optimization” firmware. The team has also sent three responsible disclosures to VNISH, Luxor, and Braiins, giving each party 30 days to respond before public disclosure. MicroBT, Canaan, Auradine, Bitdeer, and ePIC are set for later audits.

Bitcoin’s mining network is going through a notable pullback in hashrate, with mining difficulty now about 14% below this year’s high, according to Blockcast. After a 0.74% downward adjustment, network difficulty stands at 126.23 T, down 1.1% from 127.62 T a year earlier and 19.1% below the all-time high of 155.97 T set in November 2025. The report says this is only the second time in Bitcoin’s history that mining difficulty has fallen below the level seen in the same period of the prior year. Unlike the 2021 drop tied to China’s nationwide mining ban, the current decline is being linked to weaker mining economics. Hashrate Index, operated by mining data platform Luxor, said soft Bitcoin prices and compressed mining revenue have pushed miners to shift capital, electricity and operating focus toward artificial intelligence and high-performance computing infrastructure. Summer curtailment in Texas and power disruptions in other major mining regions have also weighed on total hashrate. Miner profitability remains under pressure. Hashprice, a metric tracking expected daily revenue per unit of hashrate, fell to $27.66 per PH/s per day in late June, just $0.01 above this year’s February low. It has since recovered to about $31.7, while Luxor forward market pricing points to an average of roughly $31.85 by the end of December.

SBI Crypto, the Bitcoin mining arm of Japan’s SBI Group, shut down its mining pool on July 31 after five years of operation, according to a customer notice signed by CEO Hiroaki Morita. The pool stopped accepting hashpower at 7:00 a.m. Japan time on July 31, or 22:00 UTC on July 30, and any hashpower submitted after that point would not count toward final payouts. As of June 30, the pool’s seven-day average hash rate stood at about 20.9 EH/s, equal to roughly 2.2% of the Bitcoin network, but that figure had already fallen about 64% over the month leading up to the shutdown. SBI did not give a reason for the closure and instead directed customers to Braiins, Luxor Pool, or NeoPool. The timing has drawn attention because Hashrate Index data shows Foundry USA, AntPool, and F2Pool together recently accounted for about 60% of Bitcoin block production, with their share reaching around 64.8% in the week of July 20. If ViaBTC is added, the top four pools come close to 70%, reviving debate over mining concentration on Bitcoin.

Luxor and MicroBT sign a $100M hardware purchase commitment; MicroBT takes strategic stake. LuxOS firmware now supports Whatsminer M50 series, adding Power Targeting and faster curtailment recovery across over 300,000 machines.

Bitcoin mining difficulty fell 11.16% to 125.86T on Feb. 7, marking the biggest downward adjustment since China's 2021 mining crackdown as hash rate, miner revenue, and fee income weakened.

Bitcoin miners are producing coins at an average cost of $88,000 while BTC trades near $69,200, leaving an almost $19,000 gap per coin. Difficulty, hashrate, and block speed have all weakened as margins tighten.

A US winter storm pressured the power grid and pushed Bitcoin miners to curtail operations. About 200 EH/s of hash rate went offline temporarily, while Foundry USA’s hash rate fell roughly 60%, slowing block production to more than 12 minutes at one point.