The Patent Claim at issue
In the interests of informed debate...
The original application was filed on 9 June 2005:
1. A computer implemented method of resisting the spread of unwanted code and data in an electronic file, the method comprising:
receiving an incoming electronic file wherein the incoming electronic file is an email having plural parts from a sender,
each part of said file containing content data in a pre-determined data file type,
each data file type having an associated set of rules;
said rules including the rules making up the file type specification and additional rules constraining the values and/or ranges that content and parameters can take on;
determining a purported predetermined data file type of each part;
parsing the content data of each part in accordance with the rules associated with the purported predetermined data file type;
determining if the content data of each part does conform to the rules associated with purported predetermined data file type;
regenerating the conforming parts of parsed content data, upon a positive determination from the determination means, to create a substitute regenerated electronic file in the purported predetermined data file type, said substitute regenerated electronic file containing the regenerated content data;
blocking the parts of the parsed content data that do not conform to the rules associated with the purported predetermined data file type so as to block them from inclusion in the substitute regenerated electronic file;
storing a list of file types and sources associated with said file types that are not considered a threat; forwarding the non conforming parts to a threat filter;
determining by the threat filter for each non conforming part whether that non conforming part is to be allowed through on the basis of the stored list and the sender of the file and the data file type; and
allowing a non-conforming part to by pass the blocking and including the by passing non-conforming part in the substitute regenerated electronic file it determined to be allowable.
Without getting onto the details of the judgement, I don't know which feature or features were deemed not to be obvious, but it could be any.
Generally Judges are not idiots and the defendants would have tried to take this apart, but failed. Since it survived then it probably has good merit.