Encryption Patent Information Page

This web page has been created to provide details and extra information about the fight to invalidate MAZ Technologies' software patent 6,185,681. The '681 patent was issued on February 6, 2001, and is claimed to cover all application-independent or transparent encryption technologies. PC Dynamics' popular SafeHouse software for Windows is amongst the first to be accused to infringe this patent.

Official Press Release

Abstract of Patent 6,185,681

Method of transparent encryption and decryption for an electronic document management system
Cryptographic methods and systems are disclosed. The cryptographic methods provide transparent encryption and decryption of documents in an electronic document management system. The cryptographic system adds a software module to an electronic document management system which traps file I/O events and performs cryptographic functions on the relevant documents before passing control back to the electronic document management system.

Full Text of Patent 6,185,681

Recent Articles and Newsgroup Discussions

Software Writers Patently Enraged, Wired News
Patent issue seen as serious threat, Ventura County Star
Encryption Patent Stirs Up Controversy, Security Wire Digest
Encryption patent firm stakes claim on industry, The Register
Patent Claimed on System-Level Encryption, Slashdot.org

How to Contact PC Dynamics, Inc.

All comments and press inquiries should be directed to Peter Avritch, president, PC Dynamics. You may contact Mr. Avritch using the information below.

PC Dynamics, Inc.
31332 Via Colinas, #102
Westlake Village, CA 91362 USA

Phone: (818)889-1741
Fax: (818)889-1014

Visit the main SafeHouse web site.

SafeHouse Evaluation Software

Request Evaluation

PC Dynamics provides evaluation copies of SafeHouse to members of the media. If you wish to receive the download link and password to the retail version of this software, please write to PC Dynamics using the link at left. To help expedite your request, we would greatly appreciate it if you would include your complete contact information and briefly explain why you are interested in this software.

If you are not a member of the media, you are welcome to download our free trial version.

Letter to PC Dynamics from MAZ's Attorney

The following is a copy of the three-page letter sent from MAZ's attorney, Steven Sereboff, to Peter Avritch, president of PC Dynamics, Inc. This letter alleges that PC Dynamics' SafeHouse drive encryption software infringes MAZ's patent and demands a $25,000 license fee.

Letter to PC Dynamics, Page 1 (100KB)
Letter to PC Dynamics, Page 2 (118KB)
Letter to PC Dynamics, Page 3 (41KB)

PC Dynamics sent this response to MAZ's request to enter into a license agreement.

A letter was also sent to Envoy Data, a security integrator that resells PC Dynamics' SafeHouse software.

Letter to Envoy Data, Reseller of SafeHouse (58KB)

Coincidently, Koppel & Jacobs, counsel for MAZ, was the law firm used by PC Dynamics in 1987 to file for its federal trademark for the Menu Works product line. Here is the letter from Richard Koppel, senior partner, confirming our application. In 1991, Menu Works was enhanced with new security features, including application-independent disk encryption, and the name was changed to Menu Works Total Security.


Drive Encryption Software Dating Back to 1991

PC Dynamics introduced its first virtual encrypted disk software in 1991 as a component of its Menu Works Total Security product for PC DOS. This Menu Works software package also included full-disk encryption, boot protection, password access controls and a variety of other essential security features.

Full disclosure of the features contained within this product were made to the NSA when the company applied for its export license.

See User's Guide

Deja vu, We've been through this before...

Unfortunately, PC Dynamics has been down this road before. In 1994 the company was targeted as the first test of a patent claiming rights to nearly all advertising or corporate logos appearing in software products. Peter Avritch, president of PC Dynamics, decided to adopt a rare legal strategy. Instead of spending thousands of dollars fighting this bizare patent in the courts, he decided to wage his fight in the media. For Avritch, this was his home court and he knew how to play the game. In the end, the PTO invalidated the patent. Still, the cost was considerable.

News Articles from 1994 Campaign to Fight Software Advertising Patent

Listed below are numerous articles and letters of support that resulted from PC Dynamics' 1994 media campaign to invalidate the Software Advertising patent. The last link is a copy of the executive order issued by Bruce Lehman, then Commissioner of Patents for the PTO, which triggered the re-examination and subsequent invalidation of patent 5,105,184.

Los Angeles Times, 1st Article (129KB)
Los Angeles Times, 2nd Article (206KB)
The Recorder, Bay Area Law Journal, Page 1 (193KB)
The Recorder, Bay Area Law Journal, Page 2 (144KB)
The Recorder, Bay Area Law Journal, Page 3 (114KB)
New York Times (132KB)
Orange County Register (49KB)
Wall Street Journal (85KB)
Software Publishers Association, Page 1 (114KB)
Software Publishers Association, Page 2 (85KB)
Los Angeles Times, Background Article (166KB)
Executive Order by Commissioner Lehman to Re-examine (84KB)

How Much does it Cost to Fight Back?

The cost to mount a defense against a patent infringement claim can be substantial. During PC Dynamics' 1994 litigation with Software Advertising Corporation, the company retained Morrison & Foerster, a well-known firm specializing in technology and intellectual property rights. Below is a letter written by Morrison & Foerster to PC Dynamics outlining the costs which were to be anticipated. You will see that even in 1994, the costs could easily surpass $100,000 just to get through the preliminary work. Going to trial would cost even more. Attorneys for patent owners use this as leverage (or legal blackmail) to encourage defendants to enter into lucrative licensing deals simply because the cost of the license is less than the cost to challenge the patent.

Morrison & Foerster on Fees, Page 1 (87KB)
Morrison & Foerster on Fees, Page 2 (39KB)

Can't We Ask for a Re-examination?

The PTO does in fact provide a process whereby a re-examination of a patent can be requested; however, costs can still add up quickly and there are some legal pitfalls that must be taken into account. For example, prior art referenced during a re-examination which fails to invalidate a patent cannot later be introduced as evidence in court. Many attorneys don't wish to put their best evidence at risk for a process which allows little communication with the PTO's examiner and tends to favor patent owners.

The Threat of Contributory Patent Infringement

Another problem faced by defendants fighting an infringement claim is that patent owners frequently threaten clients and resellers of the accused product with contributory patent infringement. Not wanting to become party to an expensive legal battle, it's not uncommon for resellers to back away from selling the alleged infringing product. Sales drop to zero and this places even more pressure on the defendant to settle.

What About Prior Art?

When filing for a patent, the applicant is required to perform a thorough search for prior art. The examiner at the PTO is also required to perform a search for prior art.

In the case of MAZ Patent 6,185,681, not a single encryption product was referenced in the patent application which was filed in 1998. When questioned about such, Steven Sereboff, counsel for MAZ, stated to PC Dynamics that he personally performed a diligent search for prior art and similar commercial products - and found none.

PC Dynamics did a quick search and found the following:

A Cryptographic File System for Unix by Matt Blaze (1993)
Linux Journal Issue 40: TCFS: Transparent Cryptographic File System (August 1997)
Design and Implementation of a Transparent Cryptographic File System for Unix (1996)
VDDRV Encrypting Virtual Drive, Glenn Everhart, Public Domain RSX11 SIG tape (1979)

The earliest work of prior art we've discovered to date has been Glenn Everhart's 1978 virtual encrypted drive code for the DEC RSX11D. See documentation and source. Many thanks to Glenn for bringing this to our attention. Glenn has also been a great help in working to locate other meaningful material related to this case.

Do you know of any prior art applicable to this patent? If so, please contact Peter Avritch at PC Dynamics. The best examples include books, journal articles and papers presented at industry conferences and seminars.

How About Commercial or Shareware Products?

For certain, in 1998 there were dozens of software products that facilitated application-independent encryption. In fact, by that time, many early products had already become obsolete!

Filelok, Vault Corporation (1984)
Hard Disk Partition for Mac, FWB Inc. (1989)
Menu Works Total Security, PC Dynamics, Inc. (1991)
DISKREET, Norton Utilities v5 (1991)
Secure File System (1996)
PGPDisk, Phil Zimmermann
Invincible Disk, RSA Labs
For Your Eyes Only, Symantec (1996)

We won't even try to list all the current products that feature application-independent encryption. There's just too many of them. Here's a site that lists some shareware disk encryption products.

Was MAZ Truly Unaware of any Prior Art?

The question keeps coming up: How could MAZ claim in good faith that they were unaware of any prior art? As it is, the law does not require them to search for prior art; they are only required to disclose what they did know. It's perfectly legal to be ignorant - but were they?

Not disclosing known prior art to the PTO during the application process can have serious consequences for the applicant, including punitive damage awards, heavy fines and even criminal charges. MAZ could very well have a problem in this regard. The link below is to an article written by Daryl Teshima in October, 1998, which appeared in the Los Angeles Lawyer Magazine and several other legal publications. The author attempts to compare MAZ's product with competing transparent encryption solutions such as Symantec's Your Eyes Only and Phil Zimmermann's PGPDisk. Does MAZ truly expect people to believe that they never saw this review of their product? While researching this article, did the author ask MAZ how their solution differed from that offered by PGPDisk or the others?

October 1998 Article - Compares MAZ's products to other
transparent encryption products such as PGPDisk.

Further, if Daryl Teshima seemed to easily come across all these transparent encryption products in 1998, why wasn't the PTO able to do so as well?

What People are Saying...

Below are quotes and statements provided by industry experts speaking out against this patent.

Phil Zimmermann, inventor of PGP

"Does the lack of reference to obvious and well-known prior art products indicate an ignorance on the part of the patent applicant or a deliberate attempt to exclude those products from consideration as prior art by the Patent & Trademark Office?" said Phil Zimmermann, inventor of PGP (Pretty Good Privacy). "This illustrates a festering problem at the PTO with how patents get issued. This patent cannot be allowed to stand."

Bruce Schneier, Counterpane, Inc.

"The patent is a mistake, and should never have been awarded," says Bruce Schneier, CTO of Counterpane Internet Security and inventor of the Blowfish algorithm. "The Cryptographic File System, written and made available in 1993, does the same thing. I expect this thing to be overturned quickly--it's idiotic. It's abuses of the patent system like this that make it difficult for legitimate companies to develop and market technology products."

Jean-Luc Cooke, CertainKey, Inc.

“Maz Technologies is holding the security industry hostage,” said Jean-Luc Cooke, chief scientist and co-founder of CertainKey Inc. “Patenting a novel padlock design is sensible. Patenting the use of a padlock to protect a filing cabinet versus a garage door makes no sense whatsoever. There is nothing ‘novel’ about such a patent. Clearly, its purpose is not to protect innovation, but to stifle it for monetary gain.”

Glenn Everhart, software developer

Glenn Everhart, who has written security-related software since the 1970s, authored a virtual encrypted disk system in 1978 for the RSX11D from Digital Equipment Corp. He has placed his work into the public domain and allowed the source code and documentation to be distributed freely in Internet-based software collections. “It annoys me that some Johnny-come-latelies get a patent on it,” said Everhart.

Matt Blaze, AT&T Labs

"It's hard imagine how the claims in this patent got approved," said Matt Blaze, a research scientist in computer security and cryptography at AT&T Labs. "Transparent, automatic file encryption has been widely known and published -- even taught to students -- for at least a decade. In fact, I described many of the techniques claimed in this patent in a published paper on the CFS encrypting file system back in 1993 -- five years ahead of the MAZ patent application."

Krag Brotby, security consultant

Krag Brotby is a member of the Society of Competitive Intelligence Professionals, program director for the California High Tech Task Force steering committee and a member of the High Tech Criminal Investigators Association. In the 1980s, more than a decade before the Maz application was filed, Brotby was president of Vault Corp., which created FILELOK, a product that combined media fingerprinting technology with transparent file encryption. He obtained patents for the fingerprinting technologies, “but we chose to not apply for patents on transparent encryption because it was not novel then and it certainly is not novel now.”

Related Links

Below are links related to this patent which you may find useful.

MAZ Technologies, Inc.
Koppel, Jacobs, Patrick & Heybl - Counsel for MAZ