How to hack the blockchain?

A seed phrase (also known as a mnemonic phrase or seed phrase) is a set of 12 or 24 words required to recover a wallet. It is a unique list of words for each wallet that holds all the information necessary to access the balance. Typically, the wallet application itself generates the mnemonic phrase for the user to write down on paper or save in a secure electronic storage.

The words for the phrase are not randomly chosen; they are selected from a dictionary using specific calculations that virtually eliminate the probability of random matching.

To access a wallet, you only need this sequence of words, and nothing else. Following predefined algorithms, any crypto wallet can gain access to the balances associated with this phrase. The phrase of these 12 or 24 words is simply a human-readable representation of a 128-bit key (a string of zeros and ones arranged randomly). But is this enough for reliable protection?

Hacking through brute-force

The obvious question is, can't we just take more computers and simply iterate through these words or zeros and ones one by one?

Of course, we can, but let's calculate how easy or difficult that would be!

If the phrase consists of 12 words, then the number of possible combinations is 2048^12. If it consists of 24 words, then it's 2048^24.

Raising to the power, we get approximately 5.44 × 10^39 and 2.96 × 10^79, respectively. Some incomprehensible numbers, aren't they?

Let's compare it to something at least theoretically tangible. For example, if we multiply the number of observable galaxies by the average number of stars in them and by the average number of atoms in a star, we get a value close to 10^80.

In other words, the chance of getting a duplicate combination of 24 words is roughly equivalent to the chance of finding a specific atom among trillions of galaxies, each containing billions of stars. That sounds more secure, doesn't it?

Without the seed phrase, it is impossible to regain access to your assets! If the seed phrase is lost, you will lose access to your funds forever.

By the way, the same phrase in different blockchains will generate different wallet addresses. So, the seed phrase alone may not be sufficient for restoring access. Don't forget to write down which coin you created the wallet for and which software you used (there are different ways to derive addresses from a seed phrase).

Supercomputers

But we all know that there are huge devices for super-fast computations - supercomputers. And they are becoming faster and more efficient every year. Perhaps such a massive number won't be a problem for them?

Let's calculate!

As of June 2022, the world's most powerful supercomputer is the American Frontier, performing approximately 10^18 operations per second. To iterate through all the possibilities for a standard seed phrase, it would take 10^21 seconds, which is roughly equivalent to 172.5 trillion years.

For comparison, the age of our solar system is only about 4.57 billion years, which is 40,000 times less than the time it would take for the most powerful supercomputer to iterate through all the seed phrase variations.

Quantum computers

What about quantum computers? You have probably heard that they are capable of incredible computations and can easily break the Bitcoin encryptionalgorithm.

A quantum computer is a device that operates on the principles of quantum mechanics. It processes data not in bits but in qubits. In theory, such a computer can process all possible states simultaneously.

In 2019, Google made the following statement:

"Our processor takes about 200 seconds to sample one instance of a quantum circuit a million times, whereas the most advanced supercomputers would require approximately 10,000 years to perform the equivalent task."

A bold statement! Moreover, the encryption of almost all blockchains is based on so-called one-way functions (asymmetric encryption), where it is impossible to obtain the original data from the result. According to Google's statement, quantum processors will be able to calculate any one-way function within the next ten years.

A year earlier, George Friedman, a world-renowned expert in geopolitics, stated in an interview with CNBC that over time, blockchain would lose its value because sooner or later, the encryption technology would be hacked.

"I don't know any technology that remains uncracked," he said.

These forecasts can be approached with varying degrees of skepticism, but if asymmetric encryption does become outdated, we should be more concerned about our privacy, the integrity of information on websites, and our bank accounts. All messengers, browsers, and banking applications use the same asymmetric encryption for security; they just have slightly different implementations.

What's next?

Currently, quantum computers exist only as concepts and models, and it is unknown when they will be able to perform useful practical tasks. Furthermore, it is not necessary that someone will create a device specifically for breaking one-way encryption because quantum computers, like supercomputers, are highly specialized and often capable of performing only a single operation, but at an incredibly faster speed than conventional computers.

Certainly, history provides many examples of incredibly reliable encryption methods eventually being hacked. However, in such a case, a more advanced version with quantum-resistant encryption could replace today's blockchain, which developers are actively discussing. So, blockchain is not as straightforward as it may seem!