purpose of network forensics should satisfy both legal and technical requirements. For
example, it is important to guarantee whether the developed network forensic solutions are
practical and fast enough to be used in high-speed networks with heterogeneous network
architecture and devices. More important, they need to satisfy general forensics principles
such as the rules of evidence and the criteria for admissibility of novel scientific evidence
(such as the Daubert criteria) [2,3,4]. The five rules are that evidence must be
• Admissible. Must be able to be used in court or elsewhere.
• Authentic. Evidence relates to incident in relevant way.
• Complete. No tunnel vision, exculpatory evidence for alternative suspects.
• Reliable. No question about authenticity and veracity.
• Believable. Clear, easy to understand, and believable by a jury.
The evidence and the investigative network forensics techniques should satisfy the criteria for
admissibility of novel scientific evidence (Daubert v. Merrell):
• Whether the theory or technique has been reliably tested
• Whether the theory or technique has been subject to peer review and publication
• What is the known or potential rate of error of the method used?
• Whether the theory or method has been generally accepted by the scientific
community
The investigation of a cyber crime often involves cases related to homeland security,
corporate espionage, child pornography, traditional crime assisted by computer and
network technology, employee monitoring, or medical records, where privacy plays an
important role.
There are at least three distinct communities within digital forensics: law enforcement,
military, and business and industry, each of which has its own objectives and priorities. For
example, prosecution is the primary objective of the law enforcement agencies and their
practitioners and is often done after the fact. Military operations’ primary objective is to
guarantee the continuity of services, which often have strict real-time requirements. Business
and industry’s primary objectives vary significantly, many of which want to guarantee the
availability of services and put prosecution as a secondary objective.
Usually, there are three types of people who use digital evidence from network forensic
investigations: police investigators, public investigators, and private investigators. The
following are some examples:
www.syngress.com