(EN) A tamper-resistant locking mechanism for restricting access to the interior space of a rigid enclosure, comprising: a star cam twister (30) defining a longitudinal axis, said star cam twister defining a first axially extending member having a first end (31) and a second end (32) disposed opposite said first end, said first end of said star cam twister being configured with an axially extending first opening having a star-shaped transverse cross-sectional shape, said second end of said star cam twister being configured with an axially extending first cam member (38), said star cam twister being rotatably held in the interior space of the rigid enclosure, said cam member being configured for engaging a cam receiving member (46) whereby rotation of said first cam member effects opening of the locking mechanism; and a spin bushing (50), said spin bushing being rotatably held in the interior space of the rigid enclosure, said spin bushing defining a second axially extending member having a first end (51) and a second end (52) disposed opposite said first end, said spin bushing defining an axially extending second opening having a transverse cross-sectional shape that can be non-rotatably received within said star- shaped cross-sectional shape of said first opening of said star cam twister, said first end of said spin bushing being disposed apart from and facing said first end of said star cam twister. 2245 ה' בחשון התשס" ד - October 31, 2003