from
The Free On-line Dictionary of Computing (8 July 2008)
Canonical Encoding Rules
CER
<protocol, standard> (CER) A restricted variant of {BER} for
producing unequivocal {transfer syntax} for data structures
described by {ASN.1}.
Whereas {BER} gives choices as to how data values may be
encoded, CER and {DER} select just one encoding from those
allowed by the basic encoding rules, eliminating all of the
options. They are useful when the encodings must be
preserved, e.g. in security exchanges.
CER and {DER} differ in the set of restrictions that they
place on the encoder. The basic difference between CER and
{DER} is that {DER} uses definitive length form and CER uses
indefinite length form.
Documents: {ITU-T} X.690, {ISO} 8825-1.
See also {PER}.
(1998-05-19)