Why Are Quantum-Resistant Algorithms Necessary And What Are They?

by | Mar 7, 2024

Our privacy and the secure transmission of information are both protected by cryptographic methods, which keep us secure online.

However, many scientists are concerned that quantum computers may one day be able to defeat these algorithms, leaving us vulnerable to attacks from fraudsters and hackers. And sooner than most people anticipate, such quantum computers may be ready. As a result, significant effort is being made to create new kinds of algorithms that are impervious to even the most potent quantum computer that we could even conceive.

What Exactly Do These Algorithms Do?

In order to communicate data securely over the open internet, cryptographic algorithms transform readable material into a hidden, unreadable form. They are used to protect all forms of digital communication, including website traffic and email content, and are essential for online privacy, trust, and security. Today’s typical cryptographic algorithms come in many different varieties, including symmetric-key and public-key algorithms.

The type of encryption that most people understand is symmetric-key encryption. Data and communications can be scrambled using a “key,” rendering them unintelligible to anyone lacking the key. It is frequently employed to protect sensitive data kept on hard drives or in databases. If the underlying data is encrypted, even data breaches that expose databases containing sensitive user information aren’t as harmful since hackers could access the encrypted data but still won’t be able to read it.

Furthermore, public-key algorithms are crucial. They aid in overcoming the basic flaw of symmetric-key encryption, which is the requirement for a safe method of exchanging symmetric keys. Two keys are used in public-key algorithms, one of which is privately held by the receiver and the other of which is made public.

Anyone can encrypt data using the receiver’s public key, but only the receiver can decrypt it using the recipient’s private key. Because private keys are specific to the recipient, they may be used by the receiver to verify their identity. This approach can be used to send symmetric keys and can even be used in reverse for digital signatures.

Encryption is the process of turning plaintext data into gibberish that cannot be read, understood, or altered without the use of a secret key. A key is a lengthy series of illogical, erratic characters.

Symmetric Encryption :

Symmetric encryption is used when a single key is used for both both encryption and decryption.

Asymmetric Encryption :

However, Asymmetric encryption is used when two different keys are used, one to encrypt data and the other to decode it (public key encryption). The public key (encryption key) and the private key are the names of the keys (decryption key).

Why Is It Necessary For These Algorithms To Be Quantum Resistant?

Since it takes a lot of arithmetic to crack a cryptographic method, data may be kept hidden using them. A contemporary computer would need billions of years to use brute force to crack just one set of encryption keys.

However, mathematician Peter Shor discovered that the way a theoretical quantum computer would operate just so happened to match up extremely well with decrypting the type of arithmetic employed in public-key encryption in the 1990s, before quantum computers were ever really discussed.Other mathematicians were able to confirm that Shor’s Algorithm, as it came to be called, could theoretically be used by such computers to defeat public-key encryption, despite the fact that there were no quantum computers at the time. It is already generally acknowledged that the techniques we currently use for public-key encryption will be easily breakable if a real quantum computer with sufficient processing capacity is constructed. In roughly 10 to 20 years, according to the National Institute of Standards and Technology (NIST), this will be possible with quantum computers.

Fortunately, symmetric-key encryption techniques are safe since they operate differently and can be guarded by simply increasing the number of the keys they use—at least, not until mathematicians figure out a way for quantum computers to crack those as well. However, even a key size increase won’t be enough to shield current public-key encryption techniques against quantum computers. We need new algorithms.

What Would Happen If Quantum Computers Managed To Crack The Encryption We Now Use?

Yes, it’s a problem. Digital security would be seriously jeopardised if public-key encryption were to abruptly break down without a substitute. Sensitive information sent through websites would no longer be secure, for instance, because public-key encryption is used by websites to maintain secure internet connections. The blockchain technology that underpins cryptocurrencies also depends on public-key encryption to protect it, else the information on their ledgers would no longer be reliable.

There is also fear that hackers and nation-states may be storing highly confidential government or intelligence data—data they are now unable to decode—in order to be able to decrypt it in the future when quantum computers are accessible.

What Progress Has Been Made In Developing Quantum-Resistant Algorithms?

New algorithms that can survive attacks from quantum computers have being sought after by NIST in the US. Since the agency began accepting public submissions in 2016, four finalists and three backup algorithms have been selected from these. With the help of Shor’s Algorithm, these novel algorithms employ methods that can survive attacks from quantum computers.

NIST is on track to finish standardisation of the four finalists in 2024, according to project leader Dustin Moody. This process include developing standards to make sure the new algorithms are utilised appropriately and securely. The final three algorithms should be standardised by 2028.Mathematicians and cryptographers from universities and research institutes are primarily responsible for assessing candidates for the new standard. In addition to submitting suggestions for post-quantum cryptography systems, they also seek for ways to undermine them, publishing papers to share their discoveries and building on one another’s various attack strategies.

They gradually eliminate candidates who are effectively attacked or whose algorithmic flaws are exposed in this way. The standards for encryption that we presently use were developed through a process similar to this. There are no assurances, however, that these new algorithms won’t one day be vulnerable to a novel kind of cunning quantum assault or possibly even a conventional attack.

According to cryptographer Thomas Decru, “It’s difficult to establish that you can’t break it—the nonexistence of a mathematical method is hard to impossible to prove.” However, “if anything in the area of cryptography endures the test of time, the trust rises.”