Last week Protegrity announced it had filed patent infringement suits against NuBridges and Voltage Security Inc., its main competitors. Patent infringements suits are nothing new with technology companies, but this one was a little odd in that the suits were actually filed in May.We also learned of a patent infringement suit leveled against Ingrian Networks (now part of Safenet) back in April 2008. It looks like more lawsuits could be coming in the future.

Protegrity is a vendor of encryption products for data security, and many of its products have centered on protecting data that resides in databases. It has always been, in my opinion, technically innovative. And it has authored many patents during the past decade. A couple of the security startups I worked for authored similar patent claims; I was responsible for the technical side of patent development, so I reviewed and contrasted the Protegrity patents at the request of several patent authorities. Though I am not a patent attorney, I do have a basic understanding of the technologies described. There are several patents referenced in the official Protegrity press release, but the "Multi-encryption levels on a data element" is the key claim, with the others building off this central invention.

How I interpret Protegrity's multilevel patent is as follows: It describes a solution for row- or cell-level encryption of data stored in a database. What's of interest is the encryption -- or any other security measures that may be employed -- is described in another database. For the sake of simplicity, this is about the relationship between encrypted data storage and external key management. The second database describes what protections are in place, such as which encryption algorithm was used, the key, the mode of operation, or perhaps describe some masking function. By having a second database that acts as a lookup table for security means, I can implement different encryption schemes and do key rotation on a row-by-row, even element-by-element basis -- very adaptable, and a very easy way to manage complex key/encryption substitutions.

I have asked a couple of people at Protegrity to explain what this really means, specifically the use of "multilevel database encryption," but they are unable to comment at this time over and above what's in the press release. I wanted to know if they felt my interpretation was faulty, but they cannot provide any input at this time.

So there are three lingering questions:

1) What does this mean for the competition? I am not aware that the competitors use such a scheme. Or if they do, there are subtle changes to their deployment that would place them outside of the Protegrity claim.

2) Why didn't it file suit against all of the database and key management vendors? Most databases provide an API for row- and cell-level encryption, and an external key management server is, in fact, a database -- a specialized database, but a database nonetheless.

3) Why announce now? Does this mean it feels it is going to win the suit with Ingrian, or does it mean it just discovered evidence of infringement. Or is there some other motivation?

If you narrowly interpret the claims, then odds are Protegrity does not win this suit. If you broadly apply the principle that Protegrity has described in the patents, then it looks like it owns row- and cell- level database encryption when used with external key management. That would make this battle bigger than a couple of squabbling midtier security providers.

Adrian Lane is an analyst/CTO with Securosis LLC, an independent security consulting practice. Special to Dark Reading.