Hi Kathryn, On Wed, Sep 27, 2017 at 05:37:36PM -0400, Kathryn Heckman wrote:
Is there any way to retrieve the value of OP from OPc and Ki?
No, that defeats the entire purpose of having card-individual OPc values. If you could just revert that operation, there would be no [security] advantage of card-individual OPc values over a global OP value, and hence that entire option could be dropped from the specifications altogether. Regards, Harald -- - Harald Welte <laforge@gnumonks.org> http://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6)