-

M

99

-

A group of segments identifying the security service and security mechanisms applied and containing the data necessary to carry out the validation calculations.
This segment group shall specify the security service and algorithm(s) applied to the referenced EDIFACT structure. Each security header group shall be linked to a security trailer group, and additionally linked to the USY segment(s).

-

C

3

-

 

Function:

 

To identify a security algorithm, the technical usage made of it, and to contain the technical parameters required.

Notes:
1. S503, provides space for one parameter. The number of repetitions of S503 actually used will depend on the algorithm used. The order of the parameters is arbitrary but, in each case, the actual value is preceded by a coded algorithm parameter qualifier.

EDIFACT

Description

S502

SECURITY ALGORITHM

M

Use of algorithm, coded

M

an..3

=

Owner hashing

Cryptographic mode of operation, coded

C

an..3

=

DSMR

Specification of the cryptographic mode of operation used for the algorithm.

Note: The cryptographic mode of operation are the security functions authenticity, integrity and non-repudiation of origin. The digital signature includes all three security functions.

Mode of operation code list identifier

C

an..3

=

UN/CEFACT

Algorithm, coded

C

an..3

=

MD5

=

RIPEMD-160

=

SHA1

Identification of the algorithm in order to generate the hash value. The algorithms above are recommended.

Algorithm code list identifier

C

an..3

=

UN/CEFACT

Padding mechanism, coded

C

an..3

=

ISO 9796 #2 padding

Note: "ISO 9796 #2 padding" specifies the technical standard which is facilitating the security service "digital signature scheme giving message recovery" specified in DE 0525.

Padding mechanism code list identifier

C

an..3

=

UN/CEFACT

S503

ALGORITHM PARAMETER

C

Algorithm parameter qualifier

M

an..3

0554

Algorithm parameter value

M

an..512

Segment Notes:

This segment is used to identify a security algorithm, the technical usage made of it, and contains the technical parameters required in order to generate the hash value.
At least one occurrence of this segment is mandatory.

Example:
USA+1:16:1:6:1:7:1'