High Quality Content by WIKIPEDIA articles! The PKI Resource Discovery Protocol (PRQP) is an Internet protocol used for obtaining information about services associated with a X.509 Certification Authority. It is described in a draft document from the PKIX working group and is on the Experimental track. It was created by Massimiliano Pala to solve Interoperability and Usabilities issues among PKIs, specifically addressing certain problems associated with finding services and data repositories associated with a CA. Messages communicated via PRQP are encoded in ASN.1 and are usually communicated over HTTP.