B

Back up
A replicated copy of data this is made for archiving purposes and protecting against the loss of data in case of loss or damage. A back up must be stored away from the original in order to be considered secure.

Bastion Host
A bastion host is a gateway between an inside network and an outside network. Used as a security measure, the bastion host is designed to defend against attacks aimed at the inside network. Depending on a network's complexity and configuration, a single bastion host may stand guard by itself, or be part of a larger security system with different layers of protection.

Biometric
A unique and measurable characteristic of a human being used to identify an individual. A key characteristic of a biometric access system is that it must operate in real-time. An example could be a fingerprint scanner, which scans the fingerprint and compares the results instantly to a stored database of acceptable fingerprints. Other characteristics include retina scans and voice recognition. Biometrics can be used with a smart card to authenticate the user. The user's biometric information is stored on a smart card, the card is placed in a reader, and a biometric scanner reads the information to match it against that on the card. This is a fast, accurate, and highly-secure form of user authentication.

British Standard 7799 (BS7799)
BS7799 is the British standard for Information Security Management. It has now become an International Standard, ISO 17799. It is in two parts - Part 1 sets out approximately 40 objectives for Information Security, and Part 2 has about 130 controls which can be implemented to achieve those objectives.

Brute Force
An attack where all possible options are used at one time, often in a programmed sequence that attempts to use all possible passwords or decryption keys.

Bug
A problem that causes a program to crash or produce invalid output. An unpredictable outcome that can cause actions that are not planned by the programmer or the user.