Terminology

Term	Definition
Certificate Authority	A certificate authority is a trusted third party, between any two communicating elements such as network servers, that certifies that the other two or more entities involved in the intercommunication, including individual users, databases, administrators, clients, servers, are who they say they are. The certificate authority certifies each user by verifying each user's identity and grants a certificate, signing it with the certificate authority's private key.
Cipher text	Cipher text is the result of encryption performed on plain text using an algorithm, called a cipher. Cipher text is also known as encrypted or encoded information because it contains a form of the original plaintext that is unreadable by a human or computer without the proper cipher to decrypt it.
Data confidentiality	Describes any method that manipulates data so that no attacker can read it. This is commonly achieved by data encryption and keys that are only available to the parties involved in the communication.
Data integrity	Describes mechanisms that, through the use of encryption based on secret key or public key algorithms, allow the recipient of a piece of protected data to verify that the data has not been modified in transit.
Decryption	Application of a specific algorithm or cipher to encrypted data so as to render the data comprehensible to those who are authorized to see the information.

Terminology

Term	Definition
DoS	Denial of Service. A type of network attack in which the goal is to render a network service unavailable.
Encryption	Application of a specific algorithm or cipher to data so as to render the data incomprehensible to those unauthorized to see the information.
Firewall	Firewall is a collection of hardware and software that interconnects two or more networks and, at the same time, provides a central location for managing security.
Hash,Hash Algorithm	A hash algorithm is a one way function that operates on a message of arbitrary length to create a fixed-length message digest used by cryptographic services to ensure its data integrity.
Nonrepudiation	Nonrepudiation refers to the ability to ensure that a party to a contract or a communication cannot deny the authenticity of their signature on a document or the sending of a message that they originated.
Public key	A public key is one of a pair of keys that are generated by devices involved in public key infrastructure. Data encrypted with a public key can only be decrypted using the associated private key.
Spoofing	A type of attack designed to foil network security mechanisms such as filters and access lists. A spoofing attack sends a packet that claims to be from an address from which it was not actually sent.