Blowfish Encrypt/Decrypt — Free Online Blowfish Encryption Tool

Blowfish was designed by cryptographer Bruce Schneier in 1993 as a fast, patent-free alternative to DES. It quickly gained popularity in network security tools, VPN software, and password systems. Blowfish uses a 64-bit block size and a variable-length key up to 448 bits, with a complex key schedule that makes it resistant to differential and linear cryptanalysis.

While Blowfish itself has never been broken, its 64-bit block size is a limitation by modern standards. The SWEET32 attack demonstrated that birthday-bound collisions become probable after encrypting about 64GB with the same key — acceptable for many legacy applications but a concern for high-volume services. NIST recommends transitioning to AES for new applications.

Blowfish lives on most visibly through bcrypt — the password hashing function that uses Blowfish's computationally expensive key schedule to deliberately slow down hash computation. This tool implements Blowfish data encryption via node-forge for compatibility with legacy systems still using the cipher.