An observation log where changing an entry shows LOGBOOK
A contemporaneous log is worth what it can be shown to be: written at the time, untouched since. Each entry is sealed to the one before, so a later change makes the whole log produce a different seal.
The log
Use references, not names. This stays in this browser until you export it. Record the head seal somewhere separate.
Log an observation
The head seal
The fingerprint of the whole log in order. Record it somewhere separate; if it ever differs from the one you wrote down, the log has changed.
Entries
The log as a record
Doing this often? OBSCURA Case records every step in an audit trail, and keeps logs with the rest of the evidence. On its own, US$4 a month; with everything else, US$9 a month or US$79 a year. 7 days free.