Lock for a tamper resistant assembly

A tamper-resistant enclosure assembly comprising:

• a receptacle having an opening therein;
• and
• a cover configured to, in use, close said opening,
• wherein the receptacle includes at least one locking plate having a first surface facing outwardly of said receptacle and a second, opposing surface,
• wherein said locking plate further comprises a slot extending therethrough from an opening in said first surface to an exit in said second surface, said opening having a first profile and said exit having a second, different profile,
• the assembly further comprising at least one key comprising a shaft having a bit extending therefrom, wherein said key is mounted within an aperture extending through said cover from an outer face to an opposing inner face thereof, such that said bit is adjacent said inner face, and
• wherein said bit is formed of a shape memory material and is pre-configured such that its cross-sectional shape in its temporary form matches said first profile and said bit can be inserted through said slot via said opening and, upon application of a predetermined external stimulus, returns to a permanent form in which its cross-sectional shape matches said second profile and said bit can be retracted from said slot via said exit.