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Test Results for Disk Imaging Tools: EnCase 3.20

NCJ Number
Date Published
June 2003
100 pages
This document reports the results from testing EnCase 3.20, a commonly used disk imaging tool.
The Computer Forensics Tool Testing (CFTT) project is a joint effort of the National Institute of Justice (NIJ), the National Institute of Standards and Technology (NIST), the U.S. Department of Defense (DOD), the Technical Support Working Group, and other related agencies. The goal of the project is to provide measurable assurance to practitioners, researchers, and other applicable users that the tools used in computer forensics investigations provide accurate results. To accomplish this goal, specifications and test methods for computer forensics tools and subsequent testing of specific tools against those specifications must be developed. This report presents the results from testing EnCase 3.20, a disk imaging tool, against Disk Imaging Tool Specification, Version 3.1.6, developed by CFTT staff. This specification identifies the top-level disk imaging tool requirements as: the tool shall make a bit-stream duplicate or an image of an original disk or partition; the tool shall not alter the original disk; the tool shall log I/O errors; and the tool’s documentation shall be correct. Results of the test against the specification for the requirements include the following: 1) EnCase, with one exception, correctly and completely copied all disk sectors to an image file in the test cases that were run, and with two other exceptions, correctly and completely restored all disk sectors to a destination drive in the test cases that were run; 2) for all the test cases that were run, EnCase never altered the original hard drive; 3) for all the test cases that were run, EnCase always identified image files that had been modified; 4) for test cases that were run, EnCase always logged I/O/ errors; and 5) the tool documentation available was the EnCase Reference Manual, Version 3.0, Revision 3.18, and in some cases the software behavior was not documented or was ambiguous. The following three anomalies were found during the test: BIOS anomaly, logical restore anomaly, and restore size anomaly. These anomalies are described more fully in the report along with criteria for test case selection. Test results for also provided for mandatory assertions listed in the Disk Imaging Tool Specification, Version 3.1.6, as well as for optional assertions listed in the specification. Test result summaries are included at the end of the report. Tables

Date Published: June 1, 2003