``I know you believe you understand what you think I said, but I am not sure you
realize that what you heard is not what I meant.''
Richard Nixon
Authentication
The positive identification of a network entity such as a server, a
client, or a user. In SSL context the server and client
Certificate verification process.
Access Control
The restriction of access to network realms. In Apache context
usually the restriction of access to certain URLs.
Algorithm
An unambiguous formula or set of rules for solving a problem in a finite
number of steps. Algorithms for encryption are usually called Ciphers.
Certificate
A data record used for authenticating network entities such
as a server or a client. A certificate contains X.509 information pieces
about its owner (called the subject) and the signing Certificate
Authority (called the issuer), plus the owner's public key and the
signature made by the CA. Network entities verify these signatures using
CA certificates.
Certification Authority (CA)
A trusted third party whose purpose is to sign certificates for network
entities it has authenticated using secure means. Other network entities
can check the signature to verify that a CA has authenticated the bearer
of a certificate.
Certificate Signing Request (CSR)
An unsigned certificate for submission to a Certification Authority,
which signs it with the Private Key of their CA Certificate. Once
the CSR is signed, it becomes a real certificate.
Cipher
An algorithm or system for data encryption. Examples are DES, IDEA, RC4, etc.
Ciphertext
The result after a Plaintext passed a Cipher.
Configuration Directive
A configuration command that controls one or more aspects of a program's
behavior. In Apache context these are all the command names in the first
column of the configuration files.
CONNECT
A HTTP command for proxying raw data channels over HTTP. It can be used to
encapsulate other protocols, such as the SSL protocol.
Digital Signature
An encrypted text block that validates a certificate or other file. A
Certification Authority creates a signature by generating a
hash of the Public Key embedded in a Certificate, then
encrypting the hash with its own Private Key. Only the CA's
public key can decrypt the signature, verifying that the CA has
authenticated the network entity that owns the Certificate.
Export-Crippled
Diminished in cryptographic strength (and security) in order to comply
with the United States' Export Administration Regulations (EAR).
Export-crippled cryptographic software is limited to a small key size,
resulting in Ciphertext which usually can be decrypted by brute
force.
Fully-Qualified Domain-Name (FQDN)
The unique name of a network entity, consisting of a hostname and a domain
name that can resolve to an IP address. For example, www is a
hostname, whatever.com is a domain name, and
www.whatever.com is a fully-qualified domain name.
HyperText Transfer Protocol (HTTP)
The HyperText Transport Protocol is the standard transmission protocol used
on the World Wide Web.
HTTPS
The HyperText Transport Protocol (Secure), the standard encrypted
communication mechanism on the World Wide Web. This is actually just HTTP
over SSL.
Message Digest
A hash of a message, which can be used to verify that the contents of
the message have not been altered in transit.
The word or phrase that protects private key files.
It prevents unauthorized users from encrypting them. Usually it's just
the secret encryption/decryption key used for Ciphers.
Plaintext
The unencrypted text.
Private Key
The secret key in a Public Key Cryptography system, used to
decrypt incoming messages and sign outgoing ones.
Public Key
The publically available key in a Public Key Cryptography system, used to
encrypt messages bound for its owner and to decrypt signatures made by its
owner.
Public Key Cryptography
The study and application of asymmetric encryption systems, which use one
key for encryption and another for decryption. A corresponding pair of
such keys constitutes a key pair. Also called Asymmetric Crypography.
Secure Sockets Layer (SSL)
A protocol created by Netscape Communications Corporation for
general communication authentication and encryption over TCP/IP networks.
The most popular usage is HTTPS, i.e. the HyperText Transfer
Protocol (HTTP) over SSL.
Session
The context information of an SSL communication.
SSLeay
The original SSL/TLS implementation library developed by
Eric A. Young <eay@aus.rsa.com>;
see http://www.ssleay.org/
Symmetric Cryptography
The study and application of Ciphers that use a single secret key
for both encryption and decryption operations.
Transport Layer Security (TLS)
The successor protocol to SSL, created by the Internet Engineering Task
Force (IETF) for general communication authentication and encryption over
TCP/IP networks. TLS version 1 and is nearly identical with SSL version 3.
Uniform Resource Locator (URL)
The formal identifier to locate various resources on the World Wide Web.
The most popular URL scheme is http. SSL uses the
scheme https
X.509
An authentication certificate scheme recommended by the International
Telecommunication Union (ITU-T) which is used for SSL/TLS authentication.
F.A.Q. List
mod_ssl 2.8, User Manual
The Apache Interface to OpenSSL
