ISO 27001 – Annex A.10: Cryptography

What is the objective of Annex A.10.1?

Annex A.10.1 is about Cryptographic controls. The objective in this Annex A control is to ensure proper and effective use of cryptography to protect the confidentiality, authenticity and/or integrity of information. It’s an important part of the information security management system (ISMS) especially if you’d like to achieve ISO 27001 certification.

A.10.1.1 Policy on the use of Cryptographic Controls

Encryption and cryptographic controls are often seen as one of the key weapons in the security arsenal, however, on its own it is not the “silver bullet” that solves every problem. Incorrect selection of cryptographic technologies and techniques or the poor management of cryptographic material (e.g. keys and certificates) can create vulnerabilities themselves.

Encryption can slow processing and transmission of information down so it is important to understand all of the risks and balance out the controls to an adequate level whilst also still meeting performance goals.

A policy on the use of encryption can be a good place to identify the business requirements for when encryption must be used and the standards that are to be implemented. Consideration must also be given to the legal requirements around encryption.

A.10.1.2 Key Management

A good control describes how a policy on the use and protection of Cryptographic Keys should be developed and implemented through their whole lifecycle. One of the most important aspects is around the creation, distribution, changes, back up and storage of cryptographic key material through to its end of life and destruction.

Management of key material is often the weakest point for encryption and attackers may seek to attack this rather than the encryption itself. It is therefore important to have robust and secure processes around it. Dealing with compromised keys is also important and where appropriate should be tied into Annex A.16 Security Incident Management too.

Applying Encryption

ISMS.online offers some guidance and tips towards a good policy for encryption however this is one of the few areas where it is unique to your business and the operational activities where you’d use encryption.

We do have a list of partners who provide specialist advice and products around encryption so if this is an area you need help with during your implementation let us know and we can put you in touch with trusted experts too.