picklock

tiirikka A device designed to pick locks.
1623 (date of publication), w:William Shakespeare|William Shakespeare, w:Measure for Measure|Measure for Measure, Act III,

Marry, sir, he hath offended the law; and, sir, we take him to be a thief too, sir, for we have found upon him, sir, a strange picklock, which we have sent to the deputy.

A picklock of secrets.