ISM-0994

ECDH is used in preference to DH.

Topic
Asymmetric/public key algorithms
Applicable to
all

History

Priority
recommended
Mar 2024
ECDH is used in preference to DH.
The existing control relating to the use of Elliptic Curve Diffie-Hellman (ECDH) and the Elliptic Curve Digital Signature Algorithm (ECDSA), in preference to the use of Diffie-Hellman (DH) and the Digital Signature Algorithm (DSA), was amended to remove references to ECDSA and DSA following DSA being withdrawn as an ASD-approved cryptographic algorithm (AACA).
Dec 2021
ECDH and ECDSA are used in preference to DH and DSA.
Miscellaneous changes were made to rationale and security controls throughout the publication. This included:
• A review from the Using the Information Security Manual chapter through to the Guidelines for Media chapter.
• Security controls suitable for all audiences have been identified with the ‘All’ applicability marking while additional security controls suitable for just government audiences have been identified with the O, P, S and TS applicability markings.
• Security controls suitable for specific classifications have been amended to include their classification(s) in the wording of the security controls to reduce the reliance on applicability markings to confer suitability.
• Tables in security controls have been converted into prose to allow for inclusion in the SSP annex template and the XML list of security controls.
• The use of ‘official’ and ‘highly classified’ terminology has been replaced with specific classifications to remove ambiguity.
• Security controls relating to high assurance ICT equipment have had their applicability narrowed to ‘S, TS’ reflecting that they are intended for the protection of SECRET and TOP SECRET systems and data.
2015
Agencies should use ECDH and ECDSA in preference to DH and DSA.
2010
It is recommended agencies use ECDH and ECDSA before using DH and DSA.