Need-to-Know

11/09/2025

Author: Stuart Barker | ISO 27001 Expert and Thought Leader

Need-to-Know is a security principle that restricts access to information to only those individuals who require it to perform their official duties. This concept is a core element of Access Control and is based on the idea that the less exposure sensitive information has, the lower the risk of it being compromised. It is a proactive measure to protect the confidentiality of information.

Example

  • A human resources manager might have a need-to-know an employee’s salary and personal details.
  • An IT system administrator might have a need-to-know the server credentials.
  • A marketing professional would likely not have a need-to-know either of these pieces of information.

ISO 27001 Context

The Need-to-Know principle is a foundational aspect of ISO 27001 Annex A 5.15 Access Control in the ISO 27001 standard. It is often implemented through role-based access control (RBAC), where an individual’s access rights are determined by their job function and responsibilities. The principle ensures that even an authorised employee cannot access all data within an organisation.

About the author

Stuart Barker is an information security practitioner of over 30 years. He holds an MSc in Software and Systems Security and an undergraduate degree in Software Engineering. He is an ISO 27001 expert and thought leader holding both ISO 27001 Lead Implementer and ISO 27001 Lead Auditor qualifications. In 2010 he started his first cyber security consulting business that he sold in 2018. He worked for over a decade for GE, leading a data governance team across Europe and since then has gone on to deliver hundreds of client engagements and audits.

He regularly mentors and trains professionals on information security and runs a successful ISO 27001 YouTube channel where he shows people how they can implement ISO 27001 themselves. He is passionate that knowledge should not be hoarded and brought to market the first of its kind online ISO 27001 store for all the tools and templates people need when they want to do it themselves.

In his personal life he is an active and a hobbyist kickboxer.

His specialisms are ISO 27001 and SOC 2 and his niche is start up and early stage business.