The Supreme Court on Wednesday called the microcontrollers separately programmed by manufacturers in electronic voting machines (EVMs) and Voter Verifiable Paper Audit Trail (VVPAT) “agnostic”, for they do not recognise political parties or candidates but only the buttons pressed by voters.

The court recorded the submission made by the Election Commission that symbols and not software, were stored in the flash memories of the units.

“Microcontrollers in the control units (of EVMs) are agnostic. They do not recognise party or candidate names. What they recognise is the buttons pressed on the ballot units,” Justice Sanjiv Khanna said, referring to the Election Commission’s submissions.

Justice Khanna said the buttons on the ballot units were interchangeable.

“A party which got button one in a constituency would get button six in another constituency. The programming of the units are done at the manufacturer stage. Manufacturer would not know which party would get what button,” Justice Khanna surmised.

The case dealt with petitions claiming that the EVM system was opaque and prone to rigging. The Bench of Justices Khanna and Dipankar Datta had reserved the case for judgment on April 18, but convened again on Wednesday, in an unusual move, with more questions for the top poll body.

This development came even as the Lok Sabha elections are poised for the second phase of polling on April 26.

The morning session saw the Bench read out in open court the specific queries it had for the Election Commission concerning the security and functional aspects of EVMs and VVPATs. Post-lunch break, Deputy Election Commissioner Nitesh Kumar Vyas appeared in person to respond to the court’s questions, which were exactly five in number.

Vyas, on the first query as to where exactly microcontrollers were situated, said all three units comprising an EVM - ballot units, control units and VVPATs had their own microprocessors.

To the second question about whether the microcontrollers were reprogrammable, the EC official said they were “one-time programmable” at the time of manufacturing. The microprocessors could neither be changed nor physically accessed.

However, advocates Prashant Bhushan, Cheryl D’Souza and Neha Rathi, for petitioner Association for Democratic Reforms, said the EC’s claim the microprocessors were not reprogrammable was “in doubt”. The “flash memory” of these processors could be reprogrammed, Bhushan argued.

He said malicious software could be uploaded along with symbols. “When a vote is cast, the signal travels from the ballot unit to the VVPAT to the control unit. If the VVPAT has malicious software…” he pointed out.

Justice Datta intervened to note that there had not been a single instant to back this claim.

“Even if there is, the law provides for that. We cannot be the controlling authority of another constitutional authority (EC),” Justice Datta said.

Senior advocate Santosh Paul, on the petitioner side, urged the court to direct the EC to try out some anti-rigging software available in India.

“Can we issue a mandamus on suspicion?” Justice Datta reacted.

Vyas, responding to the court’s third query about Symbol Loading Units, said the Electronics Corporation of India Ltd and Bharat Electronics Ltd had manufactured 1,904 and 3,154 units so far. More could be produced roughly in a month.

On a query regarding storage of EVM-VVPATs, he said the machines were sealed and kept in strong rooms for a statutory period of 45 days after vote-counting. The strong rooms were opened after 45 days on receiving a written confirmation from the High Courts concerned that there were no election petitions contesting the results.

The last question from the court was whether VVPATs, ballot units and control units were stored together.

Vyas said the units remain separate until they are commissioned to constituencies. Pairing is done after the commissioning, he explained.

After polling, Presiding Officer seals the units and stores the EVM-VVPATs together in a strong room after getting the signatures of all the witnesses to the procedure, the senior official explained.

The case continues to be reserved for judgment.