An Omaha, Nebraska school district is now using fingerprints to log student purchases in cafeterias. The new biometric system went live this week and is being used in lunch lines at both the district’s high school and middle school.

After the district’s existing lunch program and software was discontinued, a new solution was needed. In particular, new software, as the old system was no longer supported by the vendor.

According to a report from Omaha.com, students provided their fingerprints last month as part of the registration process for the new system.

The school district sent letters to parents prior to the biometric registration, notifying them of the change in policy and explaining the new system. Of the some 3,000 students attending the two schools using biometrics, only about 20 families and a few individual high school students have chosen to opt out.

The system creates a template from the lines and swirls on the finger – it doesn’t store the fingerprint images. The template is then converted to a binary number that is encrypted and stored. According to school officials, these can also used by law enforcement agencies.

Previously, students had to show a student ID for each purchase, and students who lost their ID had to report to the office to receive a new one. The new system also ensures tat each student is paying for their own food, and only their own. For this reason, the system is also more discreet for students who qualify for free or reduced-price meals.

At the high school level, students now have just one account from which they can manage main cafeteria and convenience store purchases, rather than two separate accounts. Additionally, parents can view what students are purchasing via their online accounts.

Per the report, the new software system alone cost the district roughly $46,000, with the biometric component costing an additional $9,000.