Cisco Cisco Web Security Appliance S690 User Guide
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I R O N P O R T A S Y N C O S 6 . 3 F O R W E B U S E R G U I D E
D I G I T A L C R Y P T O G R A P HY TE R M S
To understand how encryption and decryption works, you need to understand a little bit
about cryptographic encoding techniques. Figure 10-1 describes some terms used in
cryptography that are discussed in this chapter.
about cryptographic encoding techniques. Figure 10-1 describes some terms used in
cryptography that are discussed in this chapter.
Table 10-1 Cryptography Terms and Definitions
Term
Definition
Certificate authority
An entity which issues digital certificates for use by other parties.
Certificate authorities are sometimes referred to as trusted third
parties. Certificate authorities are typically commercial companies
that charge for their services. However, some institutions and
governments have their own certificate authorities, and some offer
their services for free.
Certificate authorities are sometimes referred to as trusted third
parties. Certificate authorities are typically commercial companies
that charge for their services. However, some institutions and
governments have their own certificate authorities, and some offer
their services for free.
Cipher
An algorithm used for encoding and decoding text to make it
unreadable to any system without the appropriate key.
Ciphers work with keys to encode or decode text.
unreadable to any system without the appropriate key.
Ciphers work with keys to encode or decode text.
Ciphertext
Encoded text after a cipher has been applied to it.
Digital certificate
An electronic document that identifies and describes an
organization that has been verified and signed by a trusted
organization called a certificate authority.
A digital certificate is similar in concept to an “identification card.”
SSL uses certificates to authenticate servers.
For more information about digital certificates, see “Digital
Certificates” on page 188.
organization that has been verified and signed by a trusted
organization called a certificate authority.
A digital certificate is similar in concept to an “identification card.”
SSL uses certificates to authenticate servers.
For more information about digital certificates, see “Digital
Certificates” on page 188.
Digital signature
A checksum that verifies that a message was created by the stated
author and was not altered since its creation.
author and was not altered since its creation.
Key
A numeric parameter used by a cipher to encode or decode text.
Plaintext or cleartext
Message text in its original form, before it gets encoded by a cipher.
Public key cryptography
A system that uses two different keys for encoding and decoding
text where one key is publicly known and available and the other
key is private.
With public key cryptography, anyone can send an encoded
message to a server that has publicized its public key, but only the
recipient server can decode the message with its private key.
This is also known as asymmetric key cryptography.
text where one key is publicly known and available and the other
key is private.
With public key cryptography, anyone can send an encoded
message to a server that has publicized its public key, but only the
recipient server can decode the message with its private key.
This is also known as asymmetric key cryptography.