Cisco Cisco Web Security Appliance S670 Betriebsanweisung
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Cisco IronPort AsyncOS 7.1 for Web User Guide
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Chapter 10 Decryption Policies
Digital Cryptography Terms
Plaintext or cleartext
Message text in its original form, before it gets
encoded by a cipher.
encoded by a cipher.
Public key
cryptography
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.
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.
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.
Public key
infrastructure (PKI)
infrastructure (PKI)
An arrangement that binds public keys with respective
user identities by means of a certificate authority.
user identities by means of a certificate authority.
X.509 is a standard that is an example PKI. X.509
specifies standards for public key certificates and an
algorithm for validating certification paths.
specifies standards for public key certificates and an
algorithm for validating certification paths.
Private key
cryptography
cryptography
A system that uses the same key for encoding and
decoding text.
decoding text.
Because both sides of the transaction need the same
key, they need a secure way to communicate which key
to use in a particular communication session. Usually,
they set up secure communication using public key
cryptography and then generate a temporary
symmetric key to use for the rest of the session.
key, they need a secure way to communicate which key
to use in a particular communication session. Usually,
they set up secure communication using public key
cryptography and then generate a temporary
symmetric key to use for the rest of the session.
This is also known as symmetric key cryptography.
Root certificate
A certificate that is the topmost certificate in a
certificate tree structure.
certificate tree structure.
All certificates below the root certificate inherit the
trustworthiness of the root certificate.
trustworthiness of the root certificate.
Root certificates can be unsigned public key
certificates or self-signed certificates.
certificates or self-signed certificates.
Self-signed certificate
A digital certificate where the certificate authority is
the same as the certificate creator.
the same as the certificate creator.
Table 10-1
Cryptography Terms and Definitions (continued)
Term
Definition