|
What
is Public Key Infrastructure?
Public Key
Infrastructure (PKI) covers the use of public
key cryptography and digital certificates as
the accepted means of authentication and access
control over untrusted networks, such as the
Internet. While public key cryptography addresses
issues of data integrity and transaction privacy,
certificates address concerns in authentication
and access control.
Public key
cryptography involves the use of a pair of different,
but related, keys, which enables the conduct
of electronic commerce securely on the open telecommunications
network or the Internet. Each user has a private
key and a public key. The private key is kept
secret, known only to the user; the other key
is made public by placing it in the Public Directory
maintained by Hongkong Post.
A digital
certificate is a digital document attesting to
the binding of a public key to an individual
or other entity. It allows verification of the
claim that a specific public key does in fact
belong to a specific individual. A Hongkong Post
e-Cert contains a public key, the name of the
holder, an expiration date, a certificate serial
number and subscriber reference number.
What
is a Digital Signature?
A digital
signature, in relation to an electronic record,
is the electronic signature of a signer. It is
generated by the transformation of the electronic
record using asymmetric cryptography and a hash
function. A person having the initial untransformed
electronic record and the signer's public key
can then determine:-
- whether
the transformation was generated using the
private key that corresponds to the signer's
public key; and
- whether
the initial electronic record has been altered
since the transformation was generated.
What
is Encryption?
Encryption
is the transformation of a message into an incomprehensible
form by a key. Its purpose is to ensure privacy
by keeping information hidden from anyone for
whom it is not intended, even those who have
access to the encrypted data. Decryption is the
reverse of encryption; it is the transformation
of encrypted data back into a comprehensible
form by the corresponding key.
|
