Topic

Single-factor authentication

Applicable to

Secret

History

Dec 2021

Passphrases used for single-factor authentication on SECRET systems are at least 5 random words with a total minimum length of 17 characters.

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.

Oct 2019

Passphrases used for single-factor authentication are a minimum of 17 characters with complexity, ideally as 5 random words.

Following a rigorous review of the ability of passphrases used for single-factor authentication to withstand attack, security controls 0421 and 0422 were modified, 1426 was removed, and security controls 1557 and 1558 were added.