is a term that refers to the means of delivering a key to two parties that wish to exchange data without allowing others to see the key.

Asequential circuit contains a register of four flip-flops. initially a binary number n (0000 ≤ n ≤ 1100) is stored in the flip-flops. after a single clock pulse is applied to the circuit, the register should contain n + 0011. in other words, the function of the sequential circuit is to add 3 to the contents of a 4-bit register. design and implement this circuit using j-k flip-flops.