Будущее шифрования: AES-256 и CRYSTALS-Kyber в эпоху квантовых компьютеров.

Development of quantum computers represents a revolutionary change in computational power, capable of shaking the foundations of modern encryption standards. In this context, two encryption algorithms — AES-256 and CRYSTALS-Kyber — come to the forefront as responses to the challenges of the post-quantum era.

AES-256: the standard of symmetric encryption
AES-256, the Advanced Encryption Standard with a 256-bit key, has long been the gold standard of symmetric encryption and provides a high level of security for a wide range of digital applications. From secure transmission of confidential government documents to protecting personal communications on social networks — AES-256 is the foundation of modern data encryption. Its strength lies in the simplicity of implementation and the complexity faced by attackers trying to crack the encryption key by brute force.

Advanced capabilities of AES-256
The Advanced Encryption Standard (AES) is a widely used cryptographic system known for its security and efficiency. AES operates on data blocks of 128 bits and uses keys of 128, 192, or 256 bits for encryption. AES-256, using the longest key, offers the highest level of security among standard AES formats. Choosing a longer key exponentially increases the difficulty for potential attackers and makes breaking the cipher practically impossible using current and foreseeable technologies.
The AES-256 encryption process includes several passes or “rounds” of data processing, involving a combination of substitutions, permutations, and mixing operations. These processes transform plaintext into ciphertext through a strictly structured sequence of steps, each enhancing overall security. Each round uses a part of the key, and the entire process ensures strong data mixing, making decryption without the exact key extremely difficult.

Protectstar’s Extended AES with 512 bits
In addition to the standardized AES key lengths, Protectstar has developed an extended version of AES — Extended AES (https://www.protectstar.com/en/extended-aes) — with a 512-bit key length.
This innovation aims to increase security by lengthening the key, which theoretically increases resistance to brute-force attacks. It is important to note that such extensions go beyond the standardized AES specifications and require special implementations that must be thoroughly tested and evaluated to ensure security in various application contexts.

The introduction of a 512-bit key in the Extended AES version follows the logic that doubling the key length means a quadratic increase in the number of possible key combinations, significantly enhancing theoretical security. This is especially important in the future, as computational power continues to grow exponentially and the development of quantum computers threatens existing encryption mechanisms.

While standard AES already provides a reliable security solution, the development of Extended AES emphasizes the ongoing search for even stronger encryption methods to protect confidential data from future threats. However, when evaluating such extended systems, caution is necessary, as compatibility with existing standards and practical security of implementation are critical factors.

Simple explanation:
The difference between classical and quantum computers
Imagine you have a huge pile of Lego bricks, and your task is to find out if there is a certain combination of bricks that can build an exceptional house. If you used a classical computer, it would check each brick one by one until it finds the right combination. This could take quite a long time, especially if there are many bricks.

On the other hand, a quantum computer is like a magical ability to simultaneously pick up and check many bricks at once to find out much faster whether they can build the desired house together. This is because quantum computers use special mathematics that allows them to explore many possibilities simultaneously, rather than step by step.
Classical computers work with so-called “