Secured by mod_ssl Interface
Apache Interface to SSLeay
Includes SSLeay Encryption Software

Glossary


Authentication
The positive identification of a network entity such as a server, a client, or a user.

Access Control
The restriction of access to network realms.

Algorithm
An unambiguous formula or set of rules for solving a problem in a finite number of steps. Algorithms for encryption are called Ciphers.

Certificate
A file used for authenticating network entities under the SSL protocol. A certificate contains X.509 information pieces about its owner (called the subject) and its issuer, plus the owner's public key and a signature made by a Certification Authority (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 (CA), which signs it with its Private Key. Once the CSR is signed, it becomes a real certificate.

Cipher
An algorithm or system for encryption.

Configuration Directive
A configuration command that controls one or more aspects of a program's behavior. In Apache these are all the commands in the first column of the configuration files.

CONNECT
A proxying protocol over HTTP. It can be used to encapsulate other protocols, such as the HTTPS protocol.

Digital Signature
An encrypted text block that validates a certificate or other file. A Certification Authority (CA) 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
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.

HTTP
The Hypertext Transport Protocol, the standard transmission protocol used on the World Wide Web.

HTTPS
The Hypertext Transport Protocol (Secure), the standard encrypted communication mechanism of 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.

Pass Phrase
The word or phrase that protects private key files. It prevents unauthorized users from encrypting them.

Private Key
The secret key in a RSA key pair, used to decrypt incoming messages and sign outgoing ones.

Public Key
The publically available key in a RSA key pair, 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 Socket 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 a SSL communication.

SSLeay
An SSL/TLS implementation library developed by Eric A. Young <eay@cryptsoft.com>.

Symmetric Cryptography
The study and application of Ciphers that use a single 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.

X.509
An authentication certificate scheme recommended by the International Telegraph and Telephone Consultative Committee (ITTCC) and used in SSL/TLS authentication.