use of "nbf" in jwt-encoded VCs

Hi all,

In the "jwt-encoding" section of the VC data model 1.1
(https://www.w3.org/TR/vc-data-model/#jwt-encoding) it says:

 

"nbf MUST represent issuanceDate, encoded as a UNIX timestamp"

 

Nevertheless, according to RFC 7519 nbf means "not before"
(https://datatracker.ietf.org/doc/html/rfc7519#section-4.1.5) whereas for
the issuing time the same RFC defines the claim "iat"
(https://datatracker.ietf.org/doc/html/rfc7519#section-4.1.6)

 

So I am wondering why "nbf" was selected for representing the
"issuanceDate" and not "iat"?

 

Best,

Nikos

 

Nikos Fotiou -  <http://pages.cs.aueb.gr/~fotiou>
http://pages.cs.aueb.gr/~fotiou

Researcher - Mobile Multimedia Laboratory

Athens University of Economics and Business

 <https://mm.aueb.gr> https://mm.aueb.gr