In one implementation, a public key infrastructure utilizes a two stage revocation process for a set of data. One stage authenticates or revokes the set of data based on the status of the digital signature and another stage authenticates or revokes the set of data based on the status of an individual signature by the digital certificate. For example, a digital certificate based is assigned a certificate number. A serial number is assigned for a signature for the set of data as signed by the digital certificate. A data transmission, data packet, or install package includes the set of data, the certificate number and the serial number. Therefore, individual instances of the signature may be revoked according to serial number.