Rating
Forced entry involves the use of tools such as hammers, bolt cutters, chisels, and drills; consequently, forced entry attacks exhibit obvious signs of entry. Surreptitious attacks involve picks, bump keys, shims, unauthorized key duplication, and other bypass techniques that, when employed, do not show obvious signs of compromise.
A quantitative measure of a padlock's resistance to forced and surreptitious entry can be determined with tests developed by organizations such as ASTM, Sold Secure (United Kingdom), CEN (Europe), and TNO (The Netherlands).
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