Securing Communications and Files.

The article examines the effectiveness of the Blowfish and the Pretty Good Privacy (PGP)/GnuPG software in providing security during information transfers. Local area networks are inherently insecure in most corporate, academic, even broadband cable environments, especially with regards to e-mail. Today, there are all sorts of tools to protect information transfers: secure sockets layer (SSL) for Web, secure shells (SSH) for telnet, virtual private networks (VPN) for remote access, and smart cards that provide one-time password for network access. The Blowfish and PGP ciphers can encrypt e-mail or files, but only PGP has the ability to digitally sign information without revealing the pass-phrase. Neither is a solution for everyday messages, but both can competently secure vital and confidential communications. Blowfish is a popular and secure symmetric key cipher. However, it is much more advanced and secure than standard password protection. Technically speaking, Blowfish is a 64-bit block cipher; data encrypts and decrypts in 64-bit chunks. The encryption algorithm is then executed for at least 16 rounds or iterations. Pretty Good Privacy (PGP) is the most popular public key-based encryption scheme, first created by Phil Zimmermann in 1991 as freeware software. PGP and OpenPGP are more useful when a group of users need to communicate, but the learning curve is higher. Both ciphers can encrypt local files for temporary or archival purposes.