Introduction

You are the weakest link, goodbye

Computer security demands much more than writing secure code. By far the weakest part of any cryptosystem is not the code, or the implementation of the code, but the human link. Social engineering is a more effective attack vector than software engineering.

But the integrity of digital signatures, in particular, depends on the strength of the link between the private key and the owner of the private key. It is broken if anyone other than the owner of the private key can decrypt cyphertext encrypted with the corresponding public key.

Key Management is For Everyone

Key management is, therefore, the responsibility not of a few systems engineers or security specialists, but of everyone participating in the cryptosystem. It must, therefore, be easy enough for everyone to understand, but the concepts underlying public-key/private-key cryptography are not straightforward.

The Lock and Key metaphor

Enigma’s most significant innovation is to adopt a Lock and Key metaphor, rather than a Public Key/Private Key. A PGP Public Key is, in Enigma, a Lock, which can only be unlocked with a corresponding Key. Imagine you had a number of identical padlocks, of the type which snap shut but need a key to be opened. If you also held the only copy of the one key that could open any of them, you could distribute the padlocks to your acquaintances, who could then lock a box containing a secret message for you. Although Enigma is only a class library, and not intended to be user-facing, its metaphor can be user-facing.