Día 15 mostrando catálogo camino a la @Wo_Bitcoin Esta vez es turno de un crossover genial entre #Bitcoin y cierto fontanero bigotudo con nuestro querido Proof of Work. Aún recuerdo la cara de @BitMaker_ cuando la vio el año pasado 🤩 La fuerza del POW, señoras y señores !

Liquid hack explained. Liquid has confidential transactions that hide the amounts for improved privacy. A bug in how these transactions are validated caused inflation of Liquid BTC (L-BTC) and allowed hackers to empty the entire side chain. Liquid nodes don't see the amounts of a confidential transaction, so to make sure that the transaction is still valid and doesn't cause inflation nodes check something called a balance proof and a range proof. The balance proof establish that sum of the input amounts equal the output amounts, i.e., that "x L-BTC going in and x L-BTC going out". But there's a catch. Only relying on a balance proof isn't enough. You also need the range proof. The range proof establishes that a hidden output amount falls within a positive range. That means a valid output must be at least 1 L-sat and at most 2^64 − 1 L-sats. Range proofs make sure that you can't mint "negative L-BTC". Why is this even necessary? Remember, the amounts are hidden and a hidden negative amount would allow extra positive outputs to balance against it. Without a range proof, a transaction could say "I've put 1 L-BTC in, and I'm taking two outputs out: one with 4000 L-BTC and one with -3999 L-BTC)." This is going to cause a disaster in a little bit. Once the balance proof, the range proof, and other validations pass, a transaction is regarded as valid and can pass consensus. However, because especially the range proof is computationally expensive, Liquid nodes cache the result of a successful range proof in memory. Essentially, the node remembers "I saw this range proof before and it was valid, all good!". In order to recognize the same range proof later on, you need to assign a label to it. This is called a cache key. This cache key is the actual cause of the bug. The way this cache key was constructed allowed two different transactions to collide on their cache key. Essentially, one valid transaction (1 L-BTC in, 1 L-BTC out) had the same cache key as an invalid transaction (1 L-BTC in, 4000 L-BTC out). Here's the hack: the attackers submitted the valid transaction (1 L-BTC in, 1 L-BTC out) first. Liquid nodes verified this transaction successfully, created a cache key called REKT and stored it in their cache. Then the attackers carefully crafted a second invalid transaction with (1 L-BTC in, 4000 L-BTC out) that created the same cache key REKT. Instead of validating the second transaction and realizing that it printed money out of thin air, Liquid nodes found it in their cache and said "hey I saw this transaction before, everything is fine" and that caused the inflation. The attackers then took their 4000 L-BTC and withdrew 4000 BTC onto the Bitcoin base chain. Note: I might have gotten some details wrong, and I'm aware that I simplified quite a bit. I wrote this post to help people understand what happened. Please feel free to correct me in the comments or add more details below.

El hacker de Liquid: “Por favor, primero el error. La cadena corre peligro con el último *commit* actual. Asegúrense que todos los nodos estén parcheados. Después, transferiremos los fondos de vuelta de forma segura tras confirmar la corrección.”

Does this make me a miner now?

OCEAN and Luke Dashjr announce today that, by mutual agreement, Luke Dashjr has separated from OCEAN, resigning as Chairman, Chief Technology Officer, and director. Link to the joint statement press release here: prnewswire.com/news-releases…

BITBOX DISCLOSES TWO SEVERE HARDWARE WALLET VULNERABILITIES @BitBoxSwiss says there are no reports that any of the vulnerabilities were exploited or that user funds were stolen. All disclosed issues are fixed in firmware v9.26.5, and BitBox is urging all users to update immediately. Internal security audits uncovered two severe vulnerabilities, along with new details about a previously fixed bootloader flaw. One vulnerability affecting BitBox Multi devices could allow a malicious host to execute arbitrary code and potentially install malicious firmware on devices that had not yet been set up. Another flaw in Silent Payments could allow an attacker using a malicious host device to redirect funds to an unintended address, locking the Bitcoin and potentially enabling a ransom attack. BitBox also disclosed that a previously patched bootloader vulnerability could have allowed an attacker to trick users into installing malicious firmware capable of stealing funds.