Smart card programming and development began with idea of incorporating an integrated circuit into a plastic card introduced in late 1960s. Smart card numbers were in millions in last decade with multi-application uses i.e. smart cards are used for business transactions and numerous other services. They come integrated with detection and recovery schemes from the security threat problems. This technology can provide identification, authentication, limited data storage and multi-application processing. This paper presents comparative study of threats associated with smart card based on java card technology.