Derivation of a Device-Specific Value

A method for deriving a series of device-specific values, the method comprising:

• deriving device-specific values with a plurality of challenges from a physical unclonable function realized on a circuit unit, the deriving for each challenge of the plurality of challenges comprising:
• applying the challenge to the physical unclonable function at least twice in order to produce at least two responses;
• deriving, by a processor, a categorization information item associated with the challenge from a statistical property of the at least two responses;
• and
• producing the device-specific value from the categorization information item;
• and
• producing the series of device-specific values from the respective device-specific values.

An apparatus comprising:

• a challenge generator configured to produce at least one challenge;
• a circuit unit comprising at least one physical unclonable function for deriving at least one device-specific value, the circuit unit being configured to produce at least two responses when the at least one physical unclonable function has an identical challenge of the at least one challenge applied to the at least one physical unclonable function at least twice;
• a response categorizer configured to derive a categorization information item from a statistical property of the at least two responses;
• and
• a derivation unit configured to derive the device-specific value from the categorization information item.