BIOMETRIC FINGERPRINT TERMS C
Capture
The process of collecting a biometric sample from an individual via a sensor.
CBEFF - Common Biometric Exchange File Format
A standard that provides the ability for a system to identify, and interface with, multiple biometric systems, and to exchange data between system components.
Challenge Response
A method used to confirm the presence of a person by eliciting direct responses from the individual. Responses can be either voluntary or involuntary. In a voluntary response, the end user will consciously react to something that the system presents. In an involuntary response, the end user's body automatically responds to a stimulus. A challenge response can be used to protect the system against attacks.
Claim of identity
A statement that a person is or is not the source of a reference in a database. Claims can be positive (I am in the database), negative (I am not in the database) or specific (I am end user 123 in the database).
Closed-set Identification
A biometric task where an unidentified individual is known to be in the database and the system attempts to determine his/her identity. Performance is measured by the frequency with which the individual appears in the system’s top rank (or top 5, 10, etc.).
Comparison
Process of comparing a biometric reference with a previously stored reference or references in order to make an identification or verification decision.
Cooperative User
An individual that willingly provides his/her biometric to the biometric system for capture. Example: A worker submits his/her biometric to clock in and out of work.
Core Point
The "center(s)" of a fingerprint. In a whorl pattern, the core point is found in the middle of the spiral/circles. In a loop pattern, the core point is found in the top region of the innermost loop. More technically, a core point is defined as the topmost point on the innermost upwardly curving friction ridgeline. A fingerprint may have multiple cores or no cores.
Covert
An instance in which biometric samples are being collected at a location that is not known to bystanders. An example of a covert environment might involve an airport checkpoint where face images of passengers are captured and compared to a watchlist without their knowledge.
Cumulative Match Characteristic (CMC)
A method of showing measured accuracy performance of a biometric system operating in the closed-set identification task. Templates are compared and ranked based on their similarity. The CMC shows how often the individual’s template appears in the ranks (1, 5, 10, 100, etc.), based on the match rate. A CMC compares the rank (1, 5, 10, 100, etc.) versus identification rate as illustrated below.