The present document specifies policy and security requirements relating to the operation and management practices of TSPs issuing time-stamps. These policy requirements are applicable to TSPs issuing time-stamps. Such time-stamps can be used in support of digital signatures or for any application requiring to prove that a datum existed before a particular time. The present document can be used by independent bodies as the basis for confirming that a TSP can be trusted for issuing time-stamps. The present document does not specify: • protocols used to access the TSUs; NOTE 1: A time-stamping protocol is defined in IETF RFC 3161 [i.2] including optional update in IETF RFC 5816 [i.3] and profiled in ETSI EN 319 422 . • how the requirements identified herein can be assessed by an independent body; • requirements for information to be made available to such independent bodies; • requirements on such independent bodies. NOTE 2: See ETSI EN 319 403 [i.10].