In the world of digital forensics, few principles are as vital as maintaining the integrity of original data. When conducting a digital investigation whether it involves cybercrime, policy violations, or security breaches—the most important rule is to ensure that original data is never modified.
Why is this so critical? Because digital evidence must be trustworthy. If the original data is changed, even slightly, it can be rendered inadmissible in court or lose its credibility in internal investigations. This is why forensic professionals use write blockers and create exact forensic copies (also called bit-by-bit images) before analyzing any system.
Other considerations, like protecting individual privacy, keeping systems powered on, or rotating event logs, are important—but they are secondary to maintaining evidence integrity. Privacy protections and proper log management are procedural and legal necessities, but without unaltered data, the entire investigation could collapse.
In summary, the foundation of any credible digital investigation is clear: Preserve the original evidence exactly as it was found. Altering the data not only compromises the investigation but also weakens the legal or organizational case that follows.