not possible and/or the collector wants to preserve only specific items contained in the original device (specific photos/videos, etc.), as opposed to the entire media, then calculate hash values of the target files in the original device and save the target files, jointly with the hash values list, in a clean storage media, then seal the storage media with the collector’s signature on the seal. When creating such files: • Configure the device (camera/smartphone, etc.) accurately with correct time setting, GPS activated, author information added. • Add as many additional records to the original file (like metadata relevant for future authentication) and keep the original file untouched. • Ensure that, as much as possible, the hardware/software involved in the collection process is reliable and that the collector is a person with the proper capacity and training. • Produce a record of all the steps taken, hardware and software used and other relevant contextual information as supporting data (e.g. circumstances surrounding the collection of the file; notes created on the file, etc.). When seeking to obtain files created by others, it would be ideal to either retain the original device or use forensic acquisition tools used by experts.82 Obtaining the original device might however be a rare possibility (as sources are often not willing to give these devices, etc.) and many of these tools might not be easy to use for a non-trained person. Thus, for a non-official documenters we recommend the use, whenever possible, of the procedure set above for the extraction of specific files: use of hash calculation software combined with physical method (sealing of the device with source’s signature on the seal). Metadata Metadata is an important tool to verify the authenticity of digital information. Metadata is a term used to describe “data about data,” comparable to the content of catalogues and inventories used in libraries. Metadata describes the digital information by some of its basic 82 As listed at http://www.cftt.nist.gov/ 68