What are quantum-resistant algorithms and how it keeps us safe online by protecting our privacy?

Quantum computing is a relatively new endeavor in the field of computing. Research into it started back in the early 1980s, and Quantum resistant algorithms have been progressively gaining momentum in the past few years. Quantum resistant algorithms widely known as post-quantum, quantum-secure, and quantum-safe — are cryptographic algorithms that can shift off attacks from quantum computers.

Quantum computers are machines whose processing power is far outstanding even in comparison to the most powerful supercomputers available today. Traditional computers proceed information in bits — strings of 1s and 0s represented as electrical or optical pulses. As opposed, quantum computers use qubits. These are subatomic particles, typically electrons or photons. Recent public blockchains, including Bitcoin, are protected using asymmetric cryptographic algorithms. This implies a user requires a public key and a private key to access their wallet. The mathematical relationship between users' private and public keys is too complicated for traditional computers to handle. But a quantum computer can easily figure it out and gain access to users' wallets in a matter of days. Quantum computers are at present a highly specialized area. Cryptographic algorithms are what make us safe online, safeguarding our privacy and preserving the transfer of information. But experts feel they could become commonplace and, so, an imminent threat to cryptographic security by the end of the 2020s. Blockchain networks will need upgrading before this happens. That's why there is serious work undergoing to generate new types of algorithms- Quantum resistant algorithms that are resistant to even the most powerful quantum computer we can visualize.

Process of these algorithms?

Cryptographic algorithms roll readable data into a secret, unreadable form to make it safely shared on the open internet. They are utilized to secure all types of digital communication, like traffic on websites and the content of emails, and they are mandatory for basic privacy, trust, and security on the web. There are various types of standard cryptographic algorithms widely used today, including symmetric-key and public-key algorithms. Symmetric-key encryption is what people generally think of as encryption. It permits data and messages to be scrambled using a "key" so they are indecipherable to anyone without the key. It's widely used for securing sensitive data stored in databases or hard drives. Even data breaches that compromise databases full of sensitive user information aren't as bad if the underlying data is encrypted—hackers may get the encrypted data, but there's still no way to read it.

On the other hand, Public-key algorithms are too important. They help get around the fundamental drawback of symmetric-key encryption, which is that you require a secure way to share symmetric keys in the first place. Public-key algorithms apply a set of two keys, one that is privately kept by the recipient and one that is made public. The receiver's public key can be used to scramble data, which only the receiver can unscramble utilizing the private key. This method is applied to transfer symmetric keys and can even be used in reverse for digital signatures—because private keys are unique to the receiver, receivers can use them to validate their identity.

What are the repercussions if quantum computers break the encryption we currently use?

It will be worse. If public-key encryption were immediately broken without a replacement, digital security would be severely compromised. For example, websites use public-key encryption to conserve secure internet connections, so sending secret information through websites will not remain safe. Cryptocurrencies also use public-key encryption to preserve their underlying blockchain technology, so the data on their ledgers would no longer be trustworthy. There is also worry that hackers and nation-states might be hoarding highly sensitive government or intelligence data—data they can't currently decipher— to decrypt it later once quantum computers become available.

How is work on quantum-resistant progressing?

In the US, NIST has been searching for new algorithms that can withstand attacks from quantum computers. The agency started taking public submissions in 2016, and so far, these have been narrowed down to four finalists and three backup algorithms. Quantum Resistant Algorithms use techniques that can withstand attacks from quantum computers using Shor's Algorithm. Project lead Dustin Moody mentioned NIST is the perfect way to complete the standardization of the four finalists in 2024, which includes creating guidelines to ensure that the new algorithms- Quantum Resistant Algorithms are used correctly and securely. Standardization of the remaining three algorithms is expected in 2028.