Let's talk about recently attackers drained near 1000 $BTC from OFFLINE HARDWARE WALLET .

ITS IMPOSSIBLE TO HACK $BTC ?

HOW ? 👇

Why this feels impossible for me?

🟢 A normal BIP-39 seed the way most people do: 12 (or 24) words chosen from a list of 2048 possible words. The total number of possible combinations is enormous — so big that randomly guessing even one correct seed is practically impossible. That part of my thinking is completely correct for a properly generated seed.

🚨BUT ?

Here’s the critical difference that made this attack possible:

🔴Normal seed vs. the broken #Coldcard seeds:

Normal, secure 12-word seed

The device is supposed to pick truly random numbers with 128 bits of entropy.

That means there are roughly 2¹²⁸ possible seeds.

That number is so huge (about 340 undecillion) that no computer on Earth can ever try all of them. Guessing is impossible.

What the bug did?🎯

On the affected Coldcards, the firmware did not use the full hardware randomness. Instead it used a weak software random-number generator that was seeded with predictable or limited information (device identifiers, timers, etc.).

The effective randomness dropped to roughly 40 bits on the worst-affected Mk3 devices (and about 72 bits on some later models).

2⁴⁰ is only about 1 trillion possibilities.

Modern computers and cloud computing clusters can systematically generate and check that many possibilities in a reasonable amount of time (hours to days depending on resources). The attacker does not randomly try words one by one hoping to get lucky. They recreate the weak random-number process the device used and compute the possible private keys/seeds that could have been produced.

Once they have a list of possible private keys, they simply watch the public Bitcoin blockchain. When they see an address that matches one of the keys they calculated and that address has money in it, they can spend the coins. No physical access to any #Coldcard was needed. The weakness was already baked into the seed the moment it was generated years earlier.

🔴Why this does not mean the company “knew the seeds”

Coinkite did not store or know anyone’s individual seed phrases.

The problem was a long-standing coding error in how the random numbers were generated. Because the firmware is open-source, anyone who studied the old code carefully (and Coinkite themselves say AI tools likely helped) could discover that the randomness was broken and then compute the possible weak seeds offline.

It is a serious company fault — a critical bug that existed for years — but it is not evidence that Coinkite was compromised and secretly kept a list of user seeds. If that had happened, the attack pattern would look very different.

Summary in simple terms.

✅Normal seeds → impossible to guess (too many possibilities).

✅These broken seeds → far fewer possibilities because of the firmware bug → feasible for a well-resourced attacker to calculate offline.

The physical wallets stayed offline and untouched. The damage was already done at the moment the weak seed was created.

That is why this incident shocked so many people. It broke the core assumption that “if the device is offline and the seed never left it, the money is safe.” When the randomness itself is broken, that assumption fails.

If you generated a seed on a Coldcard in the affected period, the only safe path is still the official one: update to the fixed firmware, create a completely new seed, and carefully move the funds. Normal, properly generated seeds on other wallets (or on fixed Coldcard firmware) remain secure.