Hello AllWe are using a Standalone CA on Windows Server 2003.We are renewing a client certificate to extend the validity period. The client certificate is renewed succesfully and the validity period is extended but the client certificate now has a new thumbprint. In our application we are using the thumbprint of the client certificate for custom validation. Is there a way to renew the client certificate with the original thumbprint?This is my .inf file[Version]Signature= "$Windows NT$" [NewRequest]RenewalCert="9f 2a ad cb b0 c2 72 12 33 7a e2 2a f9 5e 1f 48 ee d8 85 20"ThanksAndy

Um.... no.This is really basic cryptographyHow would you expect a hash to be the same when the - serial number changed- the validity period changedYour app is poorly written and needs to be reworkedSorry, but this is very very basic X.509 certificate theoryBrian