
382 Cyberpower
comfort over the integrity of data by using hash (digest) functions. In practice,
for reasons of speed of the encryption of large volumes of transmitted data, a
combination of symmetric and asymmetric encryption is often employed with
the benets of the advantages of both methods being enjoyed, at least in part.
In order to implement a system of asymmetric encryption, use needs to
be made of a double key consisting of a private key (secret, known only to
its owner) and a public key (non-secret, available to all who might need it).
The main advantage of this approach is that there is no need to share a secret
key. On the other hand, ...