Logically reconfigurable PUFs: memory-based secure key storage

The security of hardware is essential to the prevention of cloning, theft of service and tampering, and therefore to revenue preservation. An important component of hardware security is secure key storage. The level of security provided by a key is dependent upon the effort required from an attacker to compromise the key. Since the sophistication of tools used to carry out such attacks has increased significantly, protection of traditional key storage approaches, like storing a key in non-volatile memory (NVM), decreases. To fight these attacks Hardware Intrinsic Security (HIS) can be used. An example of HIS are Physically Unclonable Functions (PUFs). In this paper we introduce a new logically reconfigurable PUF (LR-PUF), based on a memory-based PUF. This LR-PUF uses the physical properties of a PUF combined with state information that is stored in NVM. Even though this implementation requires NVM, we will prove that the LR-PUF provides significantly more security than simply storing a key in NVM. The reason for this is that reading the information in NVM will not allow an attacker to derive any information on the key