Meticulous documentation at each stage of the digital forensics process is essential to ensuring that evidence is admissible in court (see It includes information about who collected the evidence, where and how the evidence was collected, which individuals took possession of the evidence, and when they took possession of it" (Maras, 2014, p. Module 3 on Legal Frameworks and Human Rights), which is defined as "the process by which investigators preserve the crime (or incident) scene and evidence throughout the life cycle of a case. The integrity of digital devices and digital evidence can be established with a Researchers from Google, CTI Break SHA-1 Hash Encryption Function. MD5 collisions and the impact on computer forensics. 6) (seeĬertain cryptographic hash functions have weaknesses. Understanding that there are certain "circumstances where a person finds it necessary to access original data ," the United Kingdom National Police Chiefs Council notes that "the person must be competent to do so and be able to give evidence explaining the relevance and the implications of their actions" (Principle 2) (UK Association of Chief Police Officers, 2012, p. If the hash values for the original and copy match, then the contents of the duplicate are the exact same as the original. Hash value is calculated using mathematical computations here, a cryptographic hash function is used to produce a hash value. To determine whether the duplicate is an exact copy of the original a Write blocker) that is designed to prevent the alteration of data during the copying process. This obtainment of data without altering it is accomplished by creating a duplicate copy of the content of the digital device (a process known as This was highlighted by the United Kingdom National Police Chiefs Council (NPCC), formerly known as the United Kingdom Association of Chief Police Officers, as an important principle of digital forensics practice (i.e., Principle 1: "No action taken by law enforcement agencies, persons employed within those agencies or their agents should change data which may subsequently be relied upon in court") (UK Association of Chief Police Officers, 2012, p. Digital evidence is obtained without compromising the integrity of the data. These live acquisitions, however, can interfere with the normal functions of the industrial control system (e.g., by slowing down services) (see Module 6 on Practical Aspects of Cybercrime Investigations and Digital Forensics for further information).īefore conducting a live acquisition, data acquisition priorities should be identified in terms of data accessibility, as well as the value and volatility of the data.Īcquisition. For this reason, live acquisitions are conducted that collect volatile data and non-volatile data from live running systems. These systems cannot be powered down as they provide critical services. Let us consider, for example, the systems of critical infrastructures (i.e., industrial control systems). However, there are cases in which static acquisition is unfeasible. These devices are then transported back to a forensic laboratory or other facility for acquisition and analysis of digital evidence. This phase involves the collection of all digital devices that could potentially contain data of evidentiary value. Module 6 on Practical Aspects of Cybercrime Investigations and Digital Forensics for further information).Ĭollection. In this phase, the priorities for evidence collection are identified based on the value and volatility of evidence (see This phase includes the search for and recognition of relevant evidence, as well as its documentation. The proposed four phases for digital evidence handling are as follows: These guidelines included only the initial handling of digital evidence. Guidelines for Identification, Collection, Acquisition, and Preservation of Digital Evidence). In 2012, the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) published international standards for digital evidence handling (ISO/IEC 27037 International Electrotechnical Commission (IEC), an international not-for-profit organization, develop and publish international standards to harmonize practices between countries. International Organization for Standardization (ISO), an international non-governmental organization, and the Standards and best practices for digital forensics