Question 175. What is RSA Secure?

RSA Secure is a commercial software package for Windows and Macintosh computers, created by RSA Data Security, Inc. Its primary function is to encrypt the files on a user's computer or local area network. The key features of RSA Secure include ease of use, strong encryption, emergency access with key splitting, and file sharing. In more detail:

- Ease of use: RSA Secure is not a separate application; on a PC, it actually becomes part of the Windows File Manager. RSA Secure also provides a "set it and forget it" utility which automatically encrypts a user's files when the user exits Windows, shuts down his/her Macintosh, or chooses the "encrypt now" function. Individual files or entire directories can be chosen in advance for this "AutoCrypt" function, or can be encrypted on an ad hoc basis.

- Strong encryption: Individual files are encrypted using RSA's RC4 stream cipher, using 128-bit encryption for versions sold in the USA and Canada and 40-bit encryption for versions sold overseas. The emergency access RSA public/private key pair is set at 1024 bits domestically and 512 bits overseas.

- Emergency access with key splitting: RSA Secure implements a corporate-based key escrow system whereby every file that is encrypted has the random RC4 key for that file, in turn encrypted by both the user's secret key and the organization's public key. The organization's private key might then be used to decrypt a single user's files. However, to prevent potential abuse, RSA Secure implements Bloom-Shamir secret splitting, which divides the private key into discrete "shares" which are held by a number of trustees.

- File sharing: Other than protecting files on a user's computer, RSA Secure implements an additional option of encryption, allowing for ad hoc password-based encryption. A file encrypted in this manner can be transferred to another RSA Secure user for decryption. If the second user does not have RSA Secure, the encrypted file can be made a self-extracting executable file, in which case the second user runs the file, enters the password, and thus decrypts the file.

A free evaluation copy of RSA Secure can be downloaded from RSA Data Security at <>.