Public Cryptography and Private Key - Private-key Cryptography

PRIVATE-KEY CRYPTOGRAPHY

Private-key, or symmetric, encryption systems employ a single common key, possessed by those on both sides of the transaction, to both lock and unlock a message. Private keys are generally smaller, meaning they contain less bits of information, and as a result compute more quickly than do public keys. However, that also means they are more vulnerable to attack than are public keys.

Because private-key cryptography involves a series of one-to-one transactions, the concern over secrecy is paramount. For example, if a firm maintained a private-key infrastructure with several thousand clients, the company would need to ensure the secrecy of several thousand separate keys, and the opportunity for compromised security escalates. Thus private-key encryption can pose difficulties, especially over large networks of individuals, simply because key management can become a headache that costs a good deal of time and effort to manage.