ISO/IEC 27041:2015 — Information technology — Security techniques — Guidance on assuring suitability and adequacy of incident investigative methods
The fundamental purpose of the ISO27k digital forensics standards is to promote good practice methods and processes for forensic capture and investigation of digital evidence.
While individual investigators, organizations and jurisdictions may well retain certain methods, processes and controls, it is hoped that standardization will (eventually) lead to the adoption of similar if not identical approaches internationally, making it easier to compare, combine and contrast the results of such investigations even when performed by different people or organizations and potentially across different jurisdictions.
Scope and purpose
This standard “provides guidance on mechanisms for ensuring that methods and processes used in the investigation of Information Security Incidents are ‘fit for purpose’. It encapsulates best practice on defining requirements, describing methods and providing evidence that implementations of methods can be shown to satisfy requirements. It includes consideration of how vendor and third-party testing can be used to assist this assurance process. This document aims to: provide guidance on the capture and analysis of functional and non-functional requirements relating to an Information Security (IS) incident investigation; give guidance on the use of validation as a means of assuring suitability of processes involved in the investigation; provide guidance on assessing the levels of validation required and the evidence required from a validation exercise; and give guidance on how external testing and documentation can be incorporated in the validation process.” [quoted from CD2]
The primary focus of this standard is on assurance for the forensics processes and tools used in the investigation of digital evidence. Credibility, trustworthiness and integrity are fundamental requirements for all forensics methods: this standard promotes the assurance aspects of investigating digital evidence.
The standard offers guidance on assuring the suitability and adequacy of the forensic methods used to investigate digital evidence, describing methods through which all stages of the investigation process can be shown to be appropriate (proper and suitable in themselves, and correctly performed).
The standard “should be applied prior to any investigation, in the context of principles and processes (defined in ISO/IEC 27043) and sound preparation and planning (defined in ISO/IEC 27035-2) to assure the suitability of methods to be applied in the investigative processes described in ISO/IEC 27037 and ISO/IEC 27041.” [quoted from CD2, links added]
Status of the standard
The standard was published in 2015.
ISO/IEC 27037 concerns the initial capturing of digital evidence.
This standard offers guidance on the assurance aspects of digital forensics e.g. ensuring that the appropriate methods and tools are used properly.
ISO/IEC 27042 covers what happens after digital evidence has been collected i.e. its analysis and interpretation.
ISO/IEC 27043 covers the broader incident investigation activities, within which forensics usually occur.
ISO/IEC 27050 (in 4 parts) concerns electronic discovery which is pretty much what the other standards cover.
British Standard BS 10008:2008 “Evidential weight and legal admissibility of electronic information. Specification.” may also be of interest.
I am puzzled why SC 27 is developing several distinct forensics standards, covering different aspects of forensics, when they are in reality complementary parts of the same process. A multi-part standard would make more sense to me, with an overview part explaining how the jigsaw pieces fit together.