Three circuits are available for the design of a puf with256-bit long crps: * a ring oscillator based puf with 256 rings an arbiter based puf with 128 pairs of mux * a memory puf with 64kbyte array, and 64-bit long instructions to generate challenge/response pairs which circuit can maximize the puf strength (number of possible crps)? which circuit is the cheapest to build in quantity?

answer: option c. i.e. electric current flowing “downhill” from the negative electrode to the positive electrode in a battery

explanation:

the water analogy to the circuits define the pipes (water flows) to the electric current. now, we know that the electric current flows from the positive terminal to the circuit (as shown in the diagram attached).

hence, option c is the correct answer.