Physically Unclonable Function (PUF) IP

Authentication requires keys that must be embedded in devices. The traditional method is to store these keys in cryptographic chips, OTP components (one-time password) or non-volatile memories. The concern is that the stored values can be retrieved and copied using various means such as:

• Memory read-out advanced techniques;
• Reverse engineering techniques;
• Physical attacks such as Probing.

The solution to address these points is to use silicon extracted keys that are generated by a PUF. This distinguishing feature offers real protection against reverse engineering techniques

Physical Unclonable Function or Physically Unclonable Function (PUF) is known to be a solution for anti-copy applications at a silicon level. However, as they are sensitive components, they are the obvious target of physical attacks. Thus, they shall be well protected.

In order to have a good PUF, many parameters must be taken into account such as:

• Randomness, which indicates the balance of 0 and 1
• Steadiness, which indicates he stability with which a PUF produces the same responses to the same sets of challenges.
• Diffuseness, which indicates the degree of difference between the IDs generated from the different challenge sets in the same PUF
• Uniqueness, which indicates how different the generated IDs are.

A PUF is composed of two main components:

• Set of PUF entropy source based on loop, which exploits electronic noise to provide raw random bits
• PUF Manager, which controls the PUF entropy sources by giving them various challenges. The measurements returned by the PUF entropy sources are processed by the manager to generate the key.