Free Licenses

• License for Open-Source Software Implementations of OCB (Jan 9, 2013) — “License 1”
  Under this license, you are authorized to make, use, and distribute open-source software implementations of OCB. This license terminates for you if you sue someone over their open-source software implementation of OCB claiming that you have a patent covering their implementation.

  This is a non-binding summary of a legal document (the link above). The parameters of the license are specified in the license document and that document is controlling.

• General License for Non-Military Software Implementations OCB (Jan 10, 2013). — “License 2”
  This license does not authorize any military use of OCB. Aside from military uses, you are authorized to make, use, and distribute (1) any software implementation of OCB and (2) non-software implementations of OCB for noncommercial or research purposes. You are required to include notice of this license to users of your work so that they are aware of the prohibition against military use. This license terminates for you if you sue someone over an implementation of OCB authorized by this license claiming that you have a patent covering their implementation.

  This is a non-binding summary of a legal document (the link above). The parameters of the license are specified in the license document and that document is controlling.

• For other contexts, I license OCB under fair, reasonable, and non-discriminatory terms. Here is an old patent-assurance letter I wrote for the IEEE promising this. I expect licensees to pay a small, one-time fee. I intend that no solvent company should find licensing to be a significant burden. To inquire about a license other than one of the two above, just send an email to rogaway@cs.ucdavis.edu

An interesting provision of the patent grants above is that my license grant to a party terminates if that party sues someone else over their use of OCB. This is a legal scholar’s clever approach for me to discourage others not to sue you for using OCB.

Many thanks to the students and faculty at Harvard’s Berkman Center for Internet & Society. Without their expertise, I would have been clueless about how to do what I wanted to do. Thanks also to Dan Bernstein for a helpful suggestion about expanding the scope of the open-source grant.

If you have a use for OCB in mind that is not covered by the above grants but for which you believe that a paid-up license would be inappropriate, please write to me to explain.