The state JEE board authorities are considering the possibility of making it mandatory for examinees to write their papers in ballpoint pens supplied by them to prevent the use of digital pens which are used for cheating.

A committee set up by the board to suggest ways to curb cheating is trying to find out whether the system can be implemented.

"If we enforce the ban (on the use of pens brought by the candidates), we have to distribute lakhs of ballpoint pens to the examinees spread across hundreds of centres. We have to be sure that we have enough logistics to do that," JEE board chairman Sajal Dasgupta said.

The Central Board of Secondary Education, which conducts the National Entrance-cum-Eligibility Test for admission to MBBS courses across the country, has announced that from next year the candidates would have to write the exams with ballpoint pens provided by it. From 2017, Bengal would come within the ambit of the all-India test.

The fact that a committee (set up by the state board) is considering such a ban suggests the rampant use of smart cheating tools in exam halls.

A board member explained how the digital pen, a Bluetooth-enabled device which can also scan documents, is used as a cheating tool. "In the exam hall a student scans the paper with the pen and sends the digitised version to a person outside the hall through Bluetooth. The answers are dictated to the student through a radio frequency transmitter or cell phone. The student receives the answers through earplugs, which are of skin colour and has an antenna of the size of a strand of hair. It's almost impossible to detect such earplugs," he said.

Although phones are not allowed inside exam halls, students try all kinds of tricks to smuggle them in. "There is no way to tell whether a student is hiding a phone or any other device in a shoe or somewhere else as the board can't frisk the candidates," the official said.

The board has since last year been using hand-held signal detectors armed with radio frequency microwave to detect mobile phone signals in exam halls. But the system has its limitations.

A professor in Calcutta University's radio physics and electronics department said: "The closer the detector is to the source, the stronger the signal. But if the user puts the phone in 'flight' mode while someone is roaming with the detector in the room, the signal can't be detected."