In day to day life, human life cannot progress without the help of materials. From the ancient periods to the modern age, humans showed much importance to the materials and their production. As technology progressed, more and more new types of materials were found to optimize and improve the machines or tools. Many alloys and material forming techniques were invented to ease the processes or manufacturing. There are many materials which have their specific properties like hardness, toughness, machinability, weld-ability etc. One of the materials are called as "Smart materials". The term smart has been used in significance of their ability to respond according to the temperature. These materials change their shape into trained shape when temperature is raised to the trained temperature. These smart alloys are also called as "shape memory alloys". The application of Ni-Ti alloys was restricted to actuators, pseudo-electric parts and biomedical instruments. So, as the Ni-Ti alloys have good mechanical properties and reliable shape memory ability, this alloy is used to make a thermal encoded security lock. Design of thermal encoding system is made.