Preserve digital evidence through defined authority, reproducible collection, integrity verification, chain-of-custody records, and protected storage.

What you will be able to do

Distinguish collection authority from order of collection in a realistic evidence preservation and chain of custody case.
Interpret the evidence and boundary associated with integrity verification.
Choose an appropriate action involving chain of custody without exceeding the stated authority.
Verify protected evidence store through an observable result and a documented handoff.

Frame Evidence Preservation and Chain of Custody

Preserve digital evidence through defined authority, reproducible collection, integrity verification, chain-of-custody records, and protected storage.

A laptop may contain evidence of account misuse, but support staff are about to reinstall it. The responder must decide what to preserve, who may collect it, and how to avoid changing relevant state.

Keep observed facts, working assumptions, authorized actions, safety boundaries, and expected evidence separate. Begin with read-only inspection and preserve the context another analyst needs to reproduce the decision.

Collection Authority

Evidence collection must follow organizational authority, policy, privacy, legal, and operational requirements. Within evidence preservation and chain of custody, this concept answers a separate question and should retain its own evidence.

Confirm who may authorize, collect, access, transfer, and dispose of each evidence type. Apply that action to the named case before expanding the investigation or changing protected state.

Respect this boundary: do not begin invasive collection because a tool is available. The required result is specific: the case records authority and scope before collection begins.

Order of Collection

Some digital evidence changes or disappears quickly, while collection itself can modify the source. Within evidence preservation and chain of custody, this concept answers a separate question and should retain its own evidence.

Prioritize relevant volatile data and document the method, tool, time, and system state. Apply that action to the named case before expanding the investigation or changing protected state.

Respect this boundary: do not power off or interact with a source without considering evidence loss. The required result is specific: the collection method is justified and reproducible.

Integrity Verification

Cryptographic hashes can help show that a collected evidence object has not changed between checks. Within evidence preservation and chain of custody, this concept answers a separate question and should retain its own evidence.

Calculate and record an appropriate digest at acquisition and after transfer or analysis. Apply that action to the named case before expanding the investigation or changing protected state.

Respect this boundary: do not claim that a hash proves the evidence was collected correctly. The required result is specific: repeated verification shows the preserved object remains unchanged.

Chain of Custody

Chain of custody records who controlled evidence, when, where, why, and what transfer occurred. Within evidence preservation and chain of custody, this concept answers a separate question and should retain its own evidence.

Require each handoff to identify sender, receiver, timestamp, condition, and storage location. Apply that action to the named case before expanding the investigation or changing protected state.

Respect this boundary: do not leave custody gaps hidden inside informal messages. The required result is specific: every transfer is attributable from acquisition to disposition.

Protected Evidence Store

Evidence storage must protect confidentiality, integrity, availability, and required retention. Within evidence preservation and chain of custody, this concept answers a separate question and should retain its own evidence.

Use controlled access, immutable or monitored storage, backups, and an evidence inventory. Apply that action to the named case before expanding the investigation or changing protected state.

Respect this boundary: do not analyze the only evidence copy when a protected working copy is possible. The required result is specific: authorized analysis succeeds while the original remains protected.

Apply Evidence Preservation and Chain of Custody to One Case

Use the case as a bounded investigation: A laptop may contain evidence of account misuse, but support staff are about to reinstall it. The responder must decide what to preserve, who may collect it, and how to avoid changing relevant state.

First, confirm who may authorize, collect, access, transfer, and dispose of each evidence type. Then, prioritize relevant volatile data and document the method, tool, time, and system state. Keep both observations in the case record before choosing the next step.

Next, calculate and record an appropriate digest at acquisition and after transfer or analysis. After that, require each handoff to identify sender, receiver, timestamp, condition, and storage location. Finish only after you use controlled access, immutable or monitored storage, backups, and an evidence inventory.

Recap Before Practice and Prove

Collection Authority: Evidence collection must follow organizational authority, policy, privacy, legal, and operational requirements. In practice, confirm who may authorize, collect, access, transfer, and dispose of each evidence type. Preserve the boundary: do not begin invasive collection because a tool is available.

Order of Collection: Some digital evidence changes or disappears quickly, while collection itself can modify the source. In practice, prioritize relevant volatile data and document the method, tool, time, and system state. Preserve the boundary: do not power off or interact with a source without considering evidence loss.

Integrity Verification: Cryptographic hashes can help show that a collected evidence object has not changed between checks. In practice, calculate and record an appropriate digest at acquisition and after transfer or analysis. Preserve the boundary: do not claim that a hash proves the evidence was collected correctly.

Chain of Custody: Chain of custody records who controlled evidence, when, where, why, and what transfer occurred. In practice, require each handoff to identify sender, receiver, timestamp, condition, and storage location. Preserve the boundary: do not leave custody gaps hidden inside informal messages.

Protected Evidence Store: Evidence storage must protect confidentiality, integrity, availability, and required retention. In practice, use controlled access, immutable or monitored storage, backups, and an evidence inventory. Preserve the boundary: do not analyze the only evidence copy when a protected working copy is possible.