Public Key Cryptography (PKC)

Ralph Merkle, Martin Hellman, Whitfield Diffie, Public Key Cryptography (PKC) Inventors

(c) Chuck Painter/Stanford News Service
Ralph Merkle, Martin Hellman, Whitfield Diffie(1977)

Few persons can be made to believe that it is not quite an easy thing to invent a method of secret writing which shall baffle investigation. Yet it may be roundly asserted that human ingenuity cannot concoct a cipher which human ingenuity cannot resolve…

It may be observed, generally, that in such investigations the analytic ability is very forcibly called into action; and for this reason, cryptographical solutions might with great propriety be introduced into academies as the means of giving tone to the most important of the powers of the mind.

– Edgar Allan Poe; A Few Words On Secret Writing; 1841.

Public Key Cryptography (PKC) is a near magical property of information arising from the underlying mathematical structure of the universe that also conveniently enables creation of modern-day secure communication channels on the Internet.

The main feature of PKC is the use of two keys for each person, a public key and a private key, where either key can decrypt a message encrypted with the other. Each key is almost impossible to find out from the other, and if the keys are long enough the method is effectively unbreakable — according to the known laws of science.

The elegant PKC architecture enables clever creation of a secure communications system for distributed participants, which is exactly what is needed for the Internet. The technology is the basis of the field of Public Key Infrastructure (PKI), and the basis of the industry standard Rivest Shamir Adleman (RSA) encryption algorithm. The following pages provide more information.