Quantum Computer can decode cryptocurrencies like Bitcoin far more easily than initially expected: Google's researchers announced | CoinDesk JAPAN

• Recent research suggests that it may be possible to decrypt RSA encryption with a Quantum Computer using only one-twentieth of the resources previously thought necessary.
• Bitcoin uses elliptic curve cryptography, but it is also vulnerable to attacks similar to those that threaten RSA.
• Current quantum computers cannot decipher these encryption methods, but research is progressing rapidly.

According to a new research paper by Craig Gidney, a researcher at Google Quantum AI, the quantum resources required to break the widely used RSA encryption may be only one-twentieth of what was previously thought.

This research result does not specifically refer to cryptocurrencies such as Bitcoin (BTC), but rather targets the cryptographic methods that form the technological foundation supporting the security of cryptocurrency wallets and some transactions.

RSA is a public key encryption algorithm used for data encryption and decryption. RSA uses two keys that are related to each other but are different: a public key for encryption and a private key for decryption.

Bitcoin uses elliptic curve cryptography (ECC) rather than RSA. However, ECC could also be decrypted by the quantum algorithm "Shor's algorithm," which is designed to factor large numbers and solve discrete logarithm problems. These are issues that relate to the core of public key cryptography.

ECC is a method of locking and unlocking digital data using mathematical calculations called curves (which can only be computed in one direction) instead of large numbers. This can be thought of as a smaller key that is as powerful as a larger key.

A 256-bit ECC key is significantly more secure than a 2048-bit RSA key, but the threat of quantum computing increases non-linearly, so research by Mr. Gidney and others may shorten the time until such attacks become possible.

"We estimate that a 2048-bit RSA integer can be factored in less than a week by a quantum computer with less than 1 million noise qubits," Gidney wrote. This is a significant revision from the 2019 paper, which estimated that 20 million qubits would take 8 hours.

To be clear and without misunderstanding, such machines do not yet exist. The most powerful IBM quantum processor, Condor, has a strength of 1100 quantum bits (qubits), while Google's Sycamore has 53 quantum bits.

In quantum computing, the principles of quantum mechanics are utilized, using quantum bits (qubits) instead of traditional bits.

While a Bit represents either 0 or 1, a qubit can represent both 0 and 1 simultaneously due to quantum phenomena such as superposition and entanglement. This allows Quantum Computers to perform multiple calculations at the same time, potentially solving problems that are difficult for current classical computers.

"This means that the number of qubits has decreased by a factor of 20 from previous estimates," Mr. Guidoni stated in a post.

Groups like "Project Eleven" that promote research and dissemination of quantum computing are actively investigating whether the current quantum hardware can break a weakened version of Bitcoin's encryption.

The group launched a contest earlier this year offering a reward of 1 BTC to anyone who could break small ECC key sizes from 1 Bit to 25 Bit using a Quantum Computer.

The goal is not to break the encryption of Bitcoin, but to measure how close the current system can get to deciphering it.