Shared Control over Key Usage
Cryptographic keys do not only need to be well protected from copying, it is just as important to control key access and usage. Placing keys on a hardware security module helps little, if it is easier to steal the hardware than it is to break into the software. Cryptographic devices - in particular smart cards - typically use a PIN code for user authentication. Only after presentation of the correct PIN, access to contained keys is granted. A retry counter limits the number of wrong PIN presentation in order to prevent exhaustive PIN tries. While this might be sufficient for simple applications, protecting important enterprise keys requires more control. Think of CA or code-signing keys, where you don’t want a single individual to have full control. http://www.hireadrfid.com/products_info/GT-Contact-Smart-Card-343232.html Shared control over key usage is a concept that has been around for quite a while, with the four-eye principle being one of the wider known controls. ...