The Blowfish encryption algorithm is a symmetric key encryption algorithm designed by Bruce Schneier in 1993.
The characteristics of the Blowfish algorithm are fast speed, high security, and the ability to use keys of different lengths for encryption.
The encryption process of the Blowfish algorithm involves dividing the plaintext into 64-bit blocks and encrypting each block separately.
During encryption, the plaintext is encrypted using a key to produce ciphertext. During decryption, the same key is used to decrypt the ciphertext to obtain the original plaintext. The key length of the Blowfish algorithm can range from 32 to 448 bits, allowing for the use of different key lengths based on security requirements.
The security of the Blowfish algorithm mainly depends on the key length and the number of encryption rounds, so it is necessary to choose sufficiently long keys and an adequate number of encryption rounds to ensure security.
Padding Modes
- None: No padding
- PKCS7: Padding consists of a byte sequence, with each byte padded to the length of the byte sequence
- Zeros: Padding consists of bytes set to zero
- ANSIX923: Padding consists of a byte sequence, where the last byte of the sequence indicates the length and other bytes are filled with zeros
- ISO10126: Padding consists of a byte sequence, where the last byte of the sequence indicates the length and other bytes are filled with random data
For block symmetric encryption algorithms, some operation modes require the byte length of plaintext data to be a multiple of the block size, so we must pad the plaintext data before encrypting it.