Blockwise

The XXTEA (Corrected Block Tiny Encryption Algorithm) is a further evolution of the TEA and XTEA, designed to fix structural weaknesses and improve block handling. Developed by David Wheeler and Roger Needham, XXTEA departs from the classic Feistel structure and instead operates on variable-length blocks, making it more flexible for real-world data. This adjustment eliminates limitations found in TEA and XTEA, which both operate strictly on fixed 64-bit blocks.

The XTEA (eXtended Tiny Encryption Algorithm) is a symmetric block cipher designed as an improvement over the original TEA. Developed by David Wheeler and Roger Needham, XTEA was introduced to address weaknesses found in TEA, particularly its susceptibility to related-key attacks. While maintaining the same lightweight design philosophy, XTEA modifies the key schedule and round function to provide stronger security while remaining efficient and easy to implement.

The TEA (Tiny Encryption Algorithm) is a simple and efficient symmetric block cipher designed to be easy to implement while still providing a reasonable level of security. TEA operates on 64-bit blocks of data using a 128-bit key and applies a series of Feistel rounds involving bitwise operations, shifts, and additions. Its compact design makes it popular in constrained environments and educational contexts where understanding the mechanics of encryption is important.

The DES Cipher (Data Encryption Standard) is a symmetric block cipher that encrypts data in 64-bit blocks using a 56-bit key. DES was developed in the 1970s and standardized by the U.S. National Bureau of Standards. It applies 16 rounds of a Feistel network with substitution and permutation steps to securely transform plaintext into ciphertext. While largely replaced by AES for modern security, DES remains an important example of classical symmetric encryption.

The AES Cipher (Advanced Encryption Standard) is a widely used symmetric block cipher designed to securely encrypt data. AES operates on 128-bit blocks using keys of 128, 192, or 256 bits and applies a series of substitution-permutation rounds to transform plaintext into ciphertext. It is a standard encryption algorithm in modern cryptography, replacing older systems like DES and 3DES due to its higher security and efficiency.

The 3DES Cipher (Triple Data Encryption Standard) is a symmetric block cipher that applies the DES algorithm three times to each block of data, significantly increasing security compared to single DES. It operates on fixed-size blocks and uses a key that is internally expanded to 24 bytes. In this implementation, the cipher supports multiple operation modes such as ECB, CBC, CFB, and OFB, along with configurable padding schemes and output formats.

The Blowfish Cipher is a symmetric-key block cipher designed by Bruce Schneier in 1993. It was created as a fast, free alternative to older encryption standards and operates on 64-bit blocks using variable key lengths ranging from 32 bits to 448 bits. Blowfish is known for its speed in software implementations and its flexible key size, making it widely adopted in secure applications for many years.