olemus
ISO 9564, 11568:
krüptovõtme ühe osa valdamine
konfidentsiaalselt ja teistest sõltumatult, kusjuures
see osa eraldi ei ütle midagi tervikvõtme kohta
=
condition under which two or more parties separately and confidentially have custody of the constituent part of a single cryptographic key which, individually, conveys no knowledge of the resultant cryptographic key

vt ka
- shared secret 1