Penknife Features

A data security program with key management for e-mail, for use under Microsoft Windows or DOS.



Penknife takes any secret key phrase, and transforms or enciphers files into lines of jumbled ASCII text. The original file contents can be recovered from the jumble only by deciphering with exactly the same key. Files thus protected can be saved locally, archived off-site, or sent by e-mail without exposing their contents.

Penknife can automatically skip e-mail headers and signatures when deciphering, minimizing the need for manual "fix up." Enciphered alias files hold secret keys and allow them to be selected by public aliases, thus minimizing the impact of secrecy on ordinary users. Keys can be updated while users can continue to use exactly the same alias in exactly the same way. Dated alias allow access to old archived ciphertext protected by outdated keys.

Now available in Advanced, Commercial Demo, Decipher-Only and Corporate versions for DOS and Microsoft Windows. Not for export.


For greatest ease and security, the user should have an alias file. An alias file is an enciphered file of public aliases and related secret keys. The user can thus select one of many secret keys by supplying the key to the alias file plus the public alias for the desired key.

In normal operation, the user supplies the input filename, output filename (if different), the alias, and selects encipher or decipher. The program requests entry of the alias-file key, once. The program then finds the "closest" alias file, deciphers it in memory only, finds the indicated alias, then uses the secret key associated with that alias to cipher data.

The "generate" function in the advanced version automatically creates or adds to a local alias file, and will encipher the new key in a different file for transport. The transport file can be used as a beginning alias file, or added to an existing alias file, without deciphering the alias file.

Examples of Commands


Key Management

Terry Ritter, his current address, and his top page.

Last updated: 1995-08-07