Don't use text file. Use regular piece of paper, put it in tamper-evident envelope and keep register with events regarding envelopes.
When you take something from envelope, note the date, the why, the number of envelope you opened and the number of envelope you then put the piece of paper in. Every time you open envelope check with the register that the numbers agree.
When you take something from envelope, note the date, the why, the number of envelope you opened and the number of envelope you then put the piece of paper in. Every time you open envelope check with the register that the numbers agree.