Scott Daniels | October 23, 2009
Microsoft has filed its third reexamination request against U.S. Patent No. 6,259,789 which is owned by Luciano Paone and claims a computer encryption method. This most recent request sought reexamination of claims 2, 23-26 and 32-34 on the basis of nine references or combinations of references.
The PTO, however, has ordered reexamination of only claims 33-34 on the basis of only one combination of prior art. For the remaining claims, the PTO found that the references were not substantially different from those asserted in the two earlier reexaminations and that no substantial new question of patentability was raised.
The first request was filed May 16, 2008 and asked for reexamination of claims 1-6, 8, 13-15, 23-25 and 32-34. It resulted in some claims being canceled, some claims being amended, and the patentability of other claims being confirmed.
In the second request, filed June 29, 2009, reexamination was sought for only claims 17 and 26. That request was granted last month.
First Office Actions are expected later this year in the second and third reexaminations.
Microsoft clearly has not accomplished everything that it sought through these reexaminations, but the case demonstrates that a requester may file multiple requests and may selectively attack specific claims.