symmetric encryption

AES, DES, and 3DES are symmetric block cipher algorithms where the encryption and decryption processes are reversible. Common variants include AES-128, AES-192, and AES-256.
The DES algorithm is a block cipher that encrypts data in 64-bit blocks using a 56-bit key length. The same algorithm is used for both encryption and decryption.

DES relies on keeping the secret key confidential while making the algorithm itself public, including both the encryption and decryption procedures. Consequently, only an individual possessing the same key as the sender can decrypt ciphertext encrypted with DES. Therefore, breaking the DES encryption essentially amounts to searching for the correct key encoding. For a 56-bit key length, if a brute-force search is employed, the number of operations required is $2^{56}$.

3DES Algorithm

3DES is a symmetric algorithm based on DES. It encrypts a data block three times using three different keys, offering higher security strength.

AES Algorithm

The AES encryption algorithm is an advanced encryption standard in cryptography. It utilizes a symmetric block cipher structure, supporting key lengths of at least 128, 192, or 256 bits, with a fixed block length of 128 bits. The design ensures ease of implementation across various hardware and software platforms. This encryption standard was adopted by the U.S. federal government.

AES was developed specifically to replace DES, offering superior security, efficiency, and flexibility.