Package eu.europa.esig.dss.validation.process.vpfswatsp

Class POEExtraction

java.lang.Object
eu.europa.esig.dss.validation.process.vpfswatsp.POEExtraction
public class POEExtraction
extends Object
5.6.2.3 POE extraction 5.6.2.3.1 Description This building block derives POEs from a given time-stamp. Assumptions: - The time-stamp validation has returned PASSED. - The cryptographic hash function used in the time-stamp (messageImprint.hashAlgorithm) is considered reliable at current time or, if this is not the case, a PoE for that time-stamp exists for a time when the hash function has still been considered reliable. In the simple case, a time-stamp gives a POE for each data item protected by the time-stamp at the generation date/time of the token. EXAMPLE: A time-stamp on the signature value gives a POE of the signature value at the generation date/time of the time-stamp. A time-stamp can also give an indirect POE when it is computed on the hash value of some data instead of the data itself. A POE for DATA at T1 can be derived from the time-stamp: - If there is a POE for h(DATA) at a date T1,where h is a cryptographic hash function and DATA is some data (e.g. a certificate), - if h is asserted in the cryptographic constraints to be trusted until at least a date T after T1; and - if there is a POE for DATA at a date T after T1.