olemus
ISO/IEC 10181:
turvasertifikaatide järjestatud jada: esimene sertifikaat sisaldab turvateavet, iga järgmine sisaldab teavet eelmiste verifitseerimiseks
= an ordered sequence of security certificates, in which the first security certificate contains security-relevant information, and each subsequent security certificate contains security information which can be used in the verification of previous security certificates