Quantum Resistance

Sep 4, 2025 | Updated Dec 28, 2025

Quantum resistance is the development of cryptographic algorithms, such as those that secure Bitcoin, against attack from quantum computers.

What Is Quantum Resistance?

Quantum resistance is the field of building cryptographic systems that can withstand decryption by quantum computers. While powerful quantum computers are still in development today, they are theoretically capable of breaking many of the encryption algorithms currently used to secure digital communication and assets, including those underpinning Bitcoin and much of the blockchain industry.

To explain, the security of much of modern cryptography relies on mathematical problems that are practically impossible for classical computers to solve. However, a sufficiently powerful quantum computer, with exponential processinf capability, could solve these problems with relative ease, rendering these encryption standards obsolete.

This theoretically creates a risk for cryptocurrencies, as quantum computers could potentially derive a user’s private key from their public key, allowing attackers to forge digital signatures and steal funds.

How Does Quantum Resistance Work?

Quantum resistance works by replacing vulnerable cryptographic algorithms with new ones based on mathematical problems that are believed to be difficult for both classical and quantum computers to solve. These efforts are being led by organizations like the U.S. National Institute of Standards and Technology (NIST) to standardize post-quantum cryptographic algorithms.

The primary threats from quantum computing to cryptography are:

Shor’s Algorithm: A quantum algorithm that can efficiently find the prime factors of large numbers, which would break RSA and ECC encryption.
Grover’s Algorithm: A quantum algorithm that can rapidly search unstructured databases, potentially weakening symmetric encryption by making brute-force attacks more feasible.

To counter these threats, researchers are developing several new families of cryptographic algorithms:

Lattice-Based Cryptography: These algorithms are based on the difficulty of solving problems in complex, multi-dimensional geometric structures called lattices. They are a leading candidate for PQC due to their security and versatility.
Hash-Based Cryptography: This approach uses hash functions to create digital signatures. Schemes like the eXtended Merkle Signature Scheme (XMSS) are considered highly secure against quantum attacks because reversing a hash function is computationally difficult.
Code-Based Cryptography: This method relies on the difficulty of decoding a random linear code, a problem that has remained hard to solve for both classical and quantum computers for decades.
Multivariate Cryptography: This involves creating systems of equations with multiple variables, which are difficult to solve. While some encryption schemes have failed, multivariate signature schemes are considered a viable option for quantum resistance.

For a deeper dive on this topic, read the Ledger blog post, “Should Crypto Fear Quantum Computing?” to explore the potential implications of quantum computing on the cryptocurrency industry.