Cansec Zodiac 250: Standalone Biometric Access Control

The Cansec Zodiac 250 standalone fingerprint reader can enroll, manage and control access for up to 250 users (two fingerprints per user). The 250 users is an impressive number for a standalone capable fingerprint biometric.

Biometrics, according to Wikipedia, the free encyclopedia, “comprises methods for uniquely recognizing humans based upon one or more intrinsic physical or behavioral traits.” For our purposes, every human has his or her own unique physical trait - that is fingerprint’s arch, whorl, and loop. Fingerprints by agreement are the friction ridges on people’s fingers, which have sufficient uniqueness to be individualized.

Fingerprint-based access control systems use fingerprint authentication to verify a person’s identity. The access controller (administrator) already knows who the person is because the person has provided a fingerprint template to the access control system. In order to gain access, the “candidate” or offered fingerprint image is compared with one or more fingerprint templates to determine the degree to which they match.

Part of the reason this is rarely a perfect match is the fingerprints are almost never aligned perfectly when viewed and a person’s fingerprints vary as they age and lose or gain weight/fluid and other biological or environmental factors. In addition, fingerprint readers are a flat surface where it is up to the person to properly position their finger.

Here is where the problem lies. Reading the finger’s position and then comparing the number and complexity of fingerprint patterns requires a great deal of computer processing power. Computing power means speed versus time. Access control requires quick authentication of someone who can gain access. For this reason, a number of biometric companies including Cansec use a “one to one” comparison via a PIN attached to the stored fingerprint template in order to authenticate the person. This way, the candidate fingerprint image does not have to be compared to more than one template.

As a comparison, a proximity card or user code requires almost no time to process. It takes longer for the individual to find the card and swipe it or punch in the code then it takes to process the information and determine if access is granted. To practically compete, fingerprint biometrics must be as fast. Slow access can be the result for companies where many people enter and leave at specific times.

To minimize the time required to gain access, the Cansec Zodiac 250 attaches a Personal Identification Number (PIN) to the fingerprint and the backup fingerprint. By doing this, only one or two fingerprints are compared, instead of having to compare all of the fingerprints in memory (one to many).

According to Cansec, “Approximately four seconds for authentication and locking mechanism release. The time frame does not change whether there are one or 250 users programmed in the system.”

The Zodiac 250 is compact, measuring about six inches tall, by three and one half inches wide, by one and one half inches deep. The front of the unit has a 16-button keypad with the characters 1-0, ESC, ENT, PGM, F1, F2 and F3. The fingerprint reader is hooded to minimize ambient light. The tamper resistant glass prism covers the sensor.

The Zodiac 250 uses optical technology to read fingerprint minutia points. During programming, the sensor captures an image that becomes the template. At the same time a PIN is assigned to the template. Up to 500 user templates can be stored in the Zodiac 250 non-volatile memory.

The system’s level for authentication is factory set at just above average. This setting compensates for normal variation within people. As a result, this setting reduces the number of False Acceptance Rates (FAR) and has an even smaller possibility of False Reject Rates (FRR). FAR is the number of probabilities that the fingerprint biometric incorrectly matches the candidate to a non-matching template. FRR is the number of probabilities that the fingerprint biometric fails to detect a match of the candidate to the matching template. The smaller the number of FAR and FRR, the more practical the biometric is.