[Serious] Is Bitcoin secure? A reaction to “BTC whales are waking up, were their wallets hacked?"

TL;DR;

You have a much higher chance to lose your Bitcoin funds if you are keeping your BTC in an exchange. If you are keeping them on a BTC address to which you have a seedphrase, the funds are safe. The fundamentals of BTC have never been broken. Nor has the Bitcoin network seen any significant downtime. Your funds are safu, as long as you are careful with the seedphrase and the secret key and don't just allow someone to access them. You cannot bruteforce a BTC seed phrase or secret key before life on Earth is extinct given the currently available computers and ASICs.

Some details

Let's assume your seedphrase is stored securely on a piece of paper inside a fireproof safe that only you know the combination to. You never stored this seedphrase digitally, so the wallet is safe from hackers. You used the 24-word seedphrase which is harder to manage but guarantees the highest security level of a cold wallet.

A Bitcoin seedphrase is used to derive a secret key that is used to secure your Bitcoin wallet.

The BTC secret key is 64 hexadecimal characters. A secret key may look like this:

E9873D79C6D87DC0FB6A5778653389F4453213603DA61F20BD67FC233AA33262

There are 16^64 combinations. This amount can be written down as 1.1579209e+77. Don’t even try to pronounce this number*

The Earth has roughly (and we're speaking very roughly here) 7.5e+18 grains of sand, or seven quintillion, five hundred quadrillion grains.

The weight of the Sun is 4.38499439e+30 pounds

I struggle to find anything that comes even close to the size of the secret key space of SHA-256, which is the algorithm that is securing Bitcoin wallets.

An RTX 3080 GPU can process 250 million (250e+6) secret keys per second (I checked it myself using BitCrack). Let’s go crazy and assume you can rent a farm with 10k such GPUs. Or 1000 ASICs which could do a better job than GPUs.

You’d still need an unpronounceable 1.4686972e+57** years to be sure to crack a single Bitcoin wallet. By that time the life on Earth will be long extinct and we will be well on the way to the end of the universe.

Even if you scaled that operation up with billions of dollars and created a state level wallet cracking operation you'd still be looking at a timeperiod spanning past the end of life as we know it.

Closing words

Yes I know about quantum computers. They exist but they're not expected to be any threat to SHA-256 any time soon. If they are getting there we can just switch to SHA-512, there will be plenty time for that.

The 12-word seedphrase is less secure than the 24-word seedphrase if somebody is cracking the seedphrase instead of going for the secret key. It's less secure in the sense of a scientific curiosity. You're still looking at a cosmic level timespan to attack it.

* 115.792 quattuorvigintillion

**1.468 octodecillion