Chapter 1

Patent Law

On 1 June 2001, WIPO members adopted the Patent Law Treaty. However, software patents are not universally recognized. Specifically, software patents are not recognized in The Netherlands or Canada. However, US patents may in some circumstances be enforced in Canada. Since US patents cover things such as prime numbers, Openswan would likely be considered in violation of a few software patents in the US. There are at least two known US software patents covering concepts used in Openswan.

The first patent relates to NAT-Traversal, and has been patented by SSH Communications. However, they have given the IETF the following statement:

SSH Communications Security Corp hereby makes it known that it will not assert any claims in any patents issued in any country based on

—the Finnish patent application FI974665 or any patent application listing the same as a priority application; or

—the US patent application 09/333,829 or any patent application listing the same as a priority application,

—against any party that makes, uses, sells, imports, or offers for sale a conforming implementation of an IETF standards-track specification of an IPSec NAT traversal module.

This statement is limited in that SSH Communications Security Corp does not give any rights to incorporate NAT traversal technology covered by patents of SSH Communications Security Corp in implementations for any other protocols other than the IETF standards-track IPSec protocols.

Interestingly, this might actually be a benefit for the community. Microsoft cannot play 'embrace and extend' techniques unless it buys out SSH. And technically, Apple has no license to use the NAT-Traversal patent since it incorrectly implements the IETF NAT-traversal specification.

A second patent involves the DH groups and their numbers, which seem to have been patented. Information about this is unclear, and it is unlikely to be ever enforced.

A number of patents related to Elliptic Curve Cryptography are still valid (in the US only).

Expired and Bogus Patents

In 1997 the Diffie-Hellman key exchange patent and the Knapsack (and probably all public key cryptography methods) patent expired. The RSA patent expired on September 20, 2000. In 2001 a patent on Exponentiation Cryptographic Apparatus and Method expired.

There are also a lot of blatantly bogus patents that could theoretically be used against Openswan users. In 2002 for example, five years after the start of the FreeS/WAN Project, Safenet was awarded a patent that covers 'Extending cryptographic services to the kernel space of a computer operating system'. Patents like these only prove the absurdity of software patents.

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