Nachweiskette

Nachweiskette is a German term most often translated as "chain of custody" or "chain of evidence." It denotes the documented sequence of custody, control, transfer, analysis and disposition of physical or digital items so that their provenance and integrity can be verified. The concept is used in forensic science, criminal law, research data management and commercial supply chains.

A robust Nachweiskette records who handled an item, when and where handling occurred, the purpose of each transfer, relevant environmental conditions and any changes made. Common elements include identification labels, timestamps, signed transfer forms or electronic logs, tamper-evident packaging, and secure storage procedures. For digital materials, cryptographic hashes, access logs and secure backups are frequently used to demonstrate unaltered content.

Maintaining an unbroken Nachweiskette is important for evidentiary value, legal admissibility, quality assurance and reproducibility of research. Breaks or gaps in documentation can raise doubts about tampering, contamination or erroneous handling and may reduce the weight given to an item in court or in scientific review. Organizations implement standard operating procedures, training, restricted access and audit trails to preserve the chain.

Technologies such as laboratory information management systems, blockchain-based registries and digital signature systems have been applied to strengthen Nachweisketten, but procedural rigor and clear recordkeeping remain central. Legal and institutional requirements vary by jurisdiction and sector, so practitioners follow applicable laws, standards and guidelines.