Abstract: A locking system includes a tamper-resistant lock and key. The tamper-resistant lock can include a cylindrical lock body with an upper portion having an engagement surface defining a pattern of engagement features, a housing, and a hidden component sized and shaped to fit within the housing that includes an internal lock base into which the cylindrical lock body fastens and a padlock pin configured to secure the internal lock base to a hasp or staple. The key operable for use with the tamper-resistant lock can include a cylindrical key body defining an engagement cavity configured to receive the engagement surface of the cylindrical lock body, a set of complementary engagement features, a plurality of retractable engagement members, and a retractable collar at least partially covering the cylindrical key body.

Abstract: A locking system includes a tamper-resistant lock and key. The tamper-resistant lock includes a cylindrical lock body with external threading on at least a portion thereof and a bore extending into an end of the cylindrical lock body. The bore includes an engagement feature disposed on the wall that defines the bore, and the engagement feature is disposed a particular distance away from the bore opening. The key includes a collar that has a cylindrical key body that fits within the bore of the cylindrical lock body. The cylindrical key body also includes an opening defined by the collar sidewall, a retractable engagement member at least partially disposed within the opening, a spring disposed within the collar, and a plunger disposed within the collar that is operable to engage the spring and has a recess sized and shaped to accommodate the retractable engagement member.

Abstract: A locking system includes a tamper-resistant lock and key. The tamper-resistant lock includes a cylindrical lock body with external threading on at least a portion thereof and a bore extending into an end of the cylindrical lock body. The bore includes an engagement feature disposed on the wall that defines the bore, and the engagement feature is disposed a particular distance away from the bore opening. The key includes a collar that has a cylindrical key body that fits within the bore of the cylindrical lock body. The cylindrical key body also includes an opening defined by the collar sidewall, a retractable engagement member at least partially disposed within the opening, a spring disposed within the collar, and a plunger disposed within the collar that is operable to engage the spring and has a recess sized and shaped to accommodate the retractable engagement member.