Ralph Merkle and Martin Hellman Developed the first algorithm for Public Key for public-key Encryption, called t he knapsacks Algorithm. This algorithm is based on the Knapsack Problem .[this is actually a simple problem] Given a pile of Items, each with different weights, is it possible to put some of them in a bag (i.e., knapsack) in such a way that the knapsack has a certain weight? If M1, M2, M3,.., Mn are given values and S is the Sum, Find out bi so that: S = b1M1 + b2M2 + ... + bnMn Each bi can be 0 or 1. [1 indicates the item is in the knapsack and 0 indicates that it is not]. A Block of Plain text equal in length to the number of items in the pile would select the items in the knapsack. The ciphertext is the resulting sum. For example: if the knapsack is 1, 7, 8, 12, 14, 20 then the plain text and the resulting Ciphertext is shown as:
