The Apple Lawsuit Express took on a new passenger Tuesday when The PACid Group filed suit against the company alleging patent infringement. Apple was one of 19 companies named in the suit, which was filed in patent-litigation-friendly Eastern District of Texas, according to InformationWeek.

The patent, "Secure deterministic encryption key generator system and method," describes a method where, "An encryption key generator is disclosed which is highly resistant to cryptographic analysis or brute force attacks, and which accommodates the destruction of an encryption key after each use by providing for the recreation of the key without need of key directories or other encryption key storage processes."

In other words, the patent covers a method for creating a series of one-time use encryption keys used in computing devices -- more or less.

Apple was sued along with Atheros, Broadcom, Dell, Edimax, Gateway, Hewlett-Packard, Intel, Lenovo, Marvell, Realtek, Toshiba, and seven other companies.

The PACid Group describes itself as, "an encryption technology research firm, specializing in dynamic key management. PACid have invented, and patented novel encryption key management technologies, extending the value of today's encryption systems." The firm then seeks to license those patents to third party companies.

The particular patent involved in the suit, Patent #5,963,646 was filed on December 28th, 1998, and granted October 5th, 1999.

Apple has increasingly become the target of patent infringement lawsuits, an increase that has largely been in keeping with the rise of the company's success.