BRUNSWICK – The Brunswick Naval Air Station has begun distribution of computerized “smart card” IDs to 5,000 military and civilian personnel stationed at the base.

The wallet-size plastic ID, known officially as a Common Access Card, or CAC, replaces the light-green cards that members of the armed forces have used for decades as proof of identification or to shop at military facilities such as exchanges and commissaries.

The new cards, which include a bar code, circuit chip and magnetic strip to store personal information about the holder, were unveiled by the Defense Department more than a year ago.

The cards can include the holder’s fingerprint or other biometric data, said John James, base spokesman. Biometric data include fingerprints, iris patterns, face and voice recognition and hand geometry for use in identification.

The Pentagon is rolling out the cards to more than 4 million service personnel, civilian employees and contractors. About 1.5 million have already been distributed, according to the Navy.

A 32-kilobyte memory chip embedded in the CAC enables it to tie into computer networks to carry out personnel actions and provide added security.

Keyboards on government computers have a slot where the card can be inserted, James said. “You physically can’t turn your computer on in the morning without this card,” he said.

The card will provide access to medical information in case of injury or illness. The CAC also can store digital certificates, enabling users to digitally sign documents and encrypt e-mail for secure transmission.

The Navy began testing smart card technology in 1997. The following year, recruits attending basic training used a version of the CAC at the Great Lakes Naval Training Facility in Illinois for advance pay, food service and some medical and dental applications.

Officials said the new card is expected to reduce costs, streamline business processes, enhance mission effectiveness and enable the Navy to protect and share its information more effectively and efficiently.

A digital photo and a fingerprint are taken from sailors before they receive their cards; each recipient also picks a personal identification number. Unlike the old card, the CAC does not contain the holder’s signature.

Active duty military and civilian employees will receive white CACs. Selected contractors will have cards with a green stripe and foreign nationals will have a red stripe.

There are no plans at present to issue CACs to retirees and family members, who will continue to use their old cards.

The Brunswick base, home to five patrol and reconnaissance squadrons of P-3 Orion anti-submarine aircraft, was alerting retail merchants, banks and law enforcement agencies about the changeover in ID cards.