Cryptographic Key Overview
There are two types of cryptographic keys: session keys and public/private key
pairs.
Session Keys
Session keys are primarily used for data encryption/decryption and are used
with
symmetric encryption algorithms. That is, the same key is used for both encryption and
decryption.
Most of the activity involving session keys relates to keeping them secret. It
is important to keep the number of people who possess a particular session key
as small as possible (one or two people is recommended).
Public/Private Key Pairs
Key pairs are composed of two components: the
public key and the
private key. The public key is distributed far and wide while the private key, on the
other hand, is kept secret. Only the owner of the key pair is allowed to
possess the private key.
If one of the keys (the public key) is used to encrypt a message, then the
other key is required to decrypt it. Thus, if you want to send someone a message,
you can encrypt the file using their public key and be confident that no one
else will be able to read the file.
If the private key is used to sign a message, then the other key must be used
to validate the signature. For example, if you want to send someone a digitally
signed message, you would sign the message with your private key, and the
other person could verify your signature using your public key.
Unfortunately, public-key algorithms are incredibly slow and it is impractical
to use them to encrypt large amounts of data. In practice, symmetric
algorithms are used for encryption/decryption, while the public-key algorithms are used
merely to encrypt the session keys. Similarly, it is not practical to use
public-key signature algorithms to sign large messages. Instead, a hash is made of
the message and the hash value is signed.
- Software for developers
-
Delphi Components
.Net Components
Software for Android Developers
- More information resources
-
MegaDetailed.Net
Unix Manual Pages
Delphi Examples
- Databases for Amazon shops developers
-
Amazon Categories Database
Browse Nodes Database
