What is encryption in general?
Basic: Encryption is the process of converting a plaintext into a ciphertext. The ciphertext can only be converted back into the plaintext with a matching key. The conversion is finest mathematics and will not be explained further here. The field of research dealing with it is called cryptography.
What does AES256 stand for?
AES stands for “Advanced Encryption Standard” and is the successor of DES (Data Encryption Standard). It is a symmetrical encryption method, i.e. the key for encryption and decryption is identical.
The Rijndael algorithm has variable, independent block and key lengths of 128, 160, 192, 224 or 256 bits. Rijndael offers a very high level of security; it was not until more than ten years after its standardization that the first theoretically interesting, but practically irrelevant attack was found.
AES restricts the block length to 128 bits and the choice of key length to 128, 192 or 256 bits. The designations of AES256 refer to the selected key length of 256 bit. The algorithm is freely available and may be used without license fees and implemented in software and hardware.
How does this encryption work?
The mode of operation is based on a series of byte substitutions, permutations and linear transformations, which are carried out on data blocks of 16 bytes – hence the term block encryption. These operations are repeated several times, and in each of these rounds an individual round key calculated from the key is used in the calculations. If only a single bit in the key or in the data block is changed, a completely different cipher block is created – an advantage over classical stream encryption.
You can find an illustrative video of how encryption works in technical terms here: https://studyflix.de/informatik/aes-verschlusselung-1611
Fields of application for AES encryption
AES encryption is not only used in our products but also in numerous other technologies such as WLAN (WPA2), SSH and IPsec.
How secure is the AES256 encryption?
AES256 is classified as secure because there is no known algorithm that could crack it. It is also still secure against the so-called brute-force attacks. Only when the computing power of computers increases massively, one has to think about it. According to the current state of the art, trying out all combinations takes 3.31 * 10^56 years by a supercomputer.
AES256 is approved in the USA for government documents with the highest classification level.