olemus
digitaalsignatuur, mis moodustatakse sidusrežiimis signeerija ja serveri koostööna, erivorm on poolsidus signatuur
= a digital signature formed by the collaboration of a signatory and a server in online mode, a special form of which is a online-offline signature

ülevaateid
https://en.wikipedia.org/wiki/Server-based_signatures

http://aaa-sec.com/eid2/sigsupport/CentralSiginingOverview_020_en.pdf