Can we brute force bitcoin wallet seeds with a Quantum computer?
First time I heard about quantum computing; I thought Bitcoin was dead. I mean, logically, how could a system that relies on cryptography stand up to a technology that can, theoretically, break those same cryptographic systems wide open? It sounded like a doomsday for crypto.
I imagined quantum computers instantly cracking Bitcoin wallets, stealing funds, and turning the whole ecosystem into chaos.
One of the primary methods for securing Bitcoin and other cryptocurrency wallets is through the use of a seed phrase, also known as a recovery phrase or mnemonic phrase. This human-readable string of words serves as a representation of the private keys that grant access to your funds.
While a recovery phrase is sometimes referred to as a “mnemonic,” suggesting that it should be memorized, writing it down on paper is generally a more practical and reliable option, as most people are not able to remember it securely. The term seed phrase is also commonly used, because it provides the input (“seed”) to the function that generates all of a wallet’s keys.
But with rising interest in cryptocurrency and high computational power, a common question arises: Can we brute force Bitcoin wallet seeds?
In this blog, we will find out why brute-forcing Bitcoin wallet seeds is virtually impossible and why the cryptographic techniques behind them make this type of attack unfeasible.
What Is a Bitcoin Wallet Seed?
A Bitcoin wallet seed is a sequence of 12 to 24 words that represent the private keys for your cryptocurrency wallet. These words are typically generated using the BIP-39 standard, which uses a predefined list of 2048 words to map random binary data (entropy) to human-readable words. This allows you to securely back up your wallet in a format that’s easy to remember and store.
For example, a 12-word Bitcoin seed phrase might look something like this (depending on wallet):
piano region helps obey cotton marry potato clever gather lizard face dog
These seed phrases act as the master key to your wallet, allowing you to restore access to your funds, even if you lose access to your device or wallet software. But remember, “not your keys, not your crypto”
How Are Bitcoin Wallet Seeds Generated?
Basically, a cryptographic random number generator is used to create a large sequence of random bits (entropy). This entropy is then mapped to words from a predefined list.
- A 12-word seed corresponds to 128 bits of entropy.
- A 24-word seed corresponds to 256 bits of entropy.
This means that the security of your Bitcoin wallet seed is directly tied to the amount of entropy (randomness) used in generating the phrase. The more entropy there is, the more secure the seed phrase becomes, as it increases the number of potential combinations that would need to be guessed in a brute-force attack.
Why Brute-Forcing Bitcoin Wallet Seeds Is Infeasible
1. Massive Search Space
The most fundamental reason why brute-forcing Bitcoin wallet seeds is impractical is the sheer size of the search space. Let’s look at the math behind it:
- 12-Word Seed (128 Bits of Entropy): A 12-word seed phrase has 128 bits of entropy, which results in a search space of 2¹²⁸ possible combinations. In decimal form, this is approximately 3.4 × 10³⁸ possible combinations.
- 24-Word Seed (256 Bits of Entropy): A 24-word seed has 256 bits of entropy, leading to 2²⁵⁶ possible combinations, or about 1.16 × 10⁷⁷ possible combinations.
Even with the fastest supercomputers or quantum computers, testing every possible combination in a reasonable amount of time is impossible. To put things in perspective, 2¹²⁸ is an incomprehensibly large number, much larger than the total number of atoms in the observable universe!
2. Time and Resources
Let’s say you have access to an extremely fast computer capable of testing one trillion (10¹²) combinations per second. While that sounds fast, let’s break down how long it would take to brute-force these combinations:
- For a 12-word seed (128-bit): Testing 2¹²⁸ combinations at a rate of 1 trillion guesses per second would take approximately 10²⁰ years to complete. That’s much longer than the age of the universe itself!
- For a 24-word seed (256-bit): The search space is even larger, and brute-forcing this would take an even more staggering amount of time — it would be effectively impossible with any current or foreseeable technology.
3. Randomness and Unpredictability
Bitcoin wallet seeds are generated using cryptographic randomness, meaning that the bits (entropy) used to create them are designed to be unpredictable. Unlike passwords or simple codes, the randomness behind a Bitcoin wallet seed means there is no pattern or algorithm that could make guessing the correct phrase any easier.
If someone tries to guess the seed phrase, they are essentially attempting to guess a random string from a massive pool of possibilities. This randomness is a critical part of why brute-forcing Bitcoin wallet seeds is so difficult. Without any structure or predictability, there is no shortcut that can be used to reduce the search space or guess the seed faster.
4. No Way to Narrow Down the Search
Brute-forcing usually relies on narrowing down the search space using patterns or guesses based on common human behavior. For example, people often choose simple or common passwords, like “123456” or “password,” making it easier to crack them using brute force. However, Bitcoin seed phrases are not based on any such common patterns.
The word list used in BIP-39 is vast, and the words themselves are not related in a way that would make guessing easier. In fact, there’s no statistical advantage to guessing one word over another, as all 2048 words are equally likely to appear in any position in the phrase. This further complicates the brute-force attack.
Can Quantum Computers Help?
Yes, that is the comparison and that is the time scale. This is enough time to have different Satoshi Nakamoto's in 10 ^60 civilizations if one last 10,000 years :/
Quantum power is measured in qubits and the latest most powerful is one from China — unstable with 504 qbits called Tianyan-504 (I can’t confirm this), it has the potential to break some cryptographic systems, but the effects on Bitcoin wallet seeds are limited. And of course we live in a limited resource world, we do not have unlimited supply of Silicon to make the chips for that matter.
Quantum computing can theoretically speed up brute-force attacks using Grover’s algorithm.
It reduces the time required to search through a space of 2^n possibilities to 2^(n/2). This means that 2¹²⁸ possibilities for a 12-word seed could be reduced to 2⁶⁴ possibilities, and 2²⁵⁶ could be reduced to 2¹²⁸ for a 24-word seed.
However, 2⁶⁴ and 2¹²⁸ are still astronomically large numbers. Even with quantum computing, brute-forcing Bitcoin seeds is still unfeasible with current or foreseeable quantum technologies.
Post-Quantum Cryptography (PQC):
The cryptocurrency community still sees quantum computing as a threat and so they won't just sit down and watch things unfold, the community is already exploring post-quantum cryptographic solutions to safeguard digital assets against the potential threat posed by quantum computing. So even if quantum computers become more powerful, Bitcoin and other cryptocurrencies can adapt to remain secure.
Conclusion
Your virtual money is safe :)
The best way to secure your Bitcoin(crypto) wallet is to keep your seed phrase safe. Treat it like a password to your most valuable assets — don’t share it and store it in a secure location. As long as your seed phrase is kept private and secure, the chance of someone being able to brute-force your wallet is effectively zero.
Remember, not your keys, not your coins — guard it well!
