Editing Merkle–Hellman knapsack cryptosystem (section)

==History==
The concept of [[public key cryptography]] was introduced by [[Whitfield Diffie]] and Martin Hellman in 1976.<ref name=newdirections>{{cite journal|title=New directions in cryptography|journal=IEEE Transactions on Information Theory |volume=22|issue=6|pages=644|doi=10.1109/TIT.1976.1055638|author1=Whitfield Diffie|author2=Martin Hellman|year=1976|citeseerx = 10.1.1.37.9720}}</ref> At that time they proposed the general concept of a "trap-door one-way function", a function whose inverse is computationally infeasible to calculate without some secret "trap-door information"; but they had not yet found a practical example of such a function. Several specific public-key cryptosystems were then proposed by other researchers over the next few years, such as [[RSA (cryptosystem)|RSA]] in 1977 and Merkle-Hellman in 1978.<ref name="merkle_hellman">{{cite journal |last1=Merkle|first1=Ralph|last2=Hellman|first2=Martin|year=1978|title=Hiding information and signatures in trapdoor knapsacks|journal= IEEE Transactions on Information Theory|volume=24|issue=5|pages=525–530|doi=10.1109/TIT.1978.1055927}}</ref>