Digital forensics begins not with tools but with principles. Evidence that is handled carelessly is worthless no matter how skilled the later analysis, so the discipline rests on a small set of rules that protect the integrity of everything you touch.
Integrity Above All
The cardinal rule is that evidence must not be altered by the act of examining it. Investigators work from copies, verify that those copies exactly match the originals, and document every action. This discipline is what lets a finding withstand challenge, whether from an opposing expert or an internal reviewer.
Order of Volatility
Some evidence disappears the moment a system is powered off, while other evidence persists for years. Understanding this order of volatility guides what to capture first: fleeting data such as active memory before durable data such as stored files, so nothing important is lost to a hasty decision.
Authorization and Legal Basis
Forensic work carries legal weight, so it must rest on proper authorization. Whether responding to an incident on systems you administer or working under a formal legal process, having a clear, documented basis for your access protects both the investigation and the investigator.
Action Step
Write a one-page evidence-handling policy in your own words, covering integrity, the order of volatility, and authorization. Keep it as the reference you will follow for every practice exercise in this course, treating your own lab data as if it were real evidence.
Educational content only, for defensive and authorized professional use. Never test systems you do not own or lack written authorization to assess — unauthorized access is illegal. This course does not certify or license anyone.