The Supreme Court on Wednesday sought clarification from the Election Commission on certain aspects regarding the functioning of the Electronic Voting Machines (EVMs), including whether the microcontrollers fitted in them are reprogrammable, and summoned a senior poll panel official at 2 pm.

A bench of Justices Sanjiv Khanna and Dipankar Datta, which has reserved its verdict on a batch of pleas seeking complete cross-verification of votes cast using EVMs with Voter Verifiable Paper Audit Trail (VVPAT), said it needs clarification on certain aspects as there was some confusion in answers given by the EC in its 'frequently asked questions' (FAQs) on EVMs.

"We went through the FAQs. We just wanted three-four clarifications. We don’t want to be factually wrong but doubly sure in our findings and hence we thought of seeking the clarification," the bench told Additional Solicitor General Aishwarya Bhati who was appearing for the EC.

It asked Bhati to call senior Deputy Election Commissioner Nitesh Kumar Vyas at 2 PM. Vyas had earlier given a presentation to the court on the functioning of the EVMs.

It flagged some points on which the court wanted clarification which relates to storage of EVMs, microchip in the controlling unit of EVMs and other aspects.

"First clarification needed is with regard to microcontroller. Whether it is installed in controlling unit or in the VVPAT. We were under the impression that the microcontroller is the memory installed in the control unit (CU). One of the questions in the FAQs indicates that it is also installed in the VVPAT," the bench said.

The bench said that the court was informed that VVPAT has a flash memory.

"The second thing which we wanted to know is whether the microcontroller is one-time programmable. It is because there are different types of microcontrollers. It is a stand taken by the EC that the microcontroller is one-time programmable. Just confirm that," the bench told Bhati.

Justice Khanna said that third clarification relates to symbol loading units as to how many are available with the poll panel.

"We want to know how many are available with you (EC)," the bench said, adding that the fourth clarification is with regard to storage of EVMs for 45 days.

The bench said that it was told that the limitation period for filing of election petition is 30 days and hence the EVMs are stored for 45 days. "When we checked section 81 of the Representation of People Act, we found that the limitation period for filing of EVMs is 45 days. So please confirm us because it is 30 days or 45 days storage. If the limitation period is 45 days, then the corresponding period for storage needs to be enhanced," the bench pointed out.

The bench said the last point on which it needs clarification is on storage and securing of EVMs.

"When we talk of sealing and securing of EVMs, we take both the control unit and VVPAT bear the seals and are not restricted to the control unit. Somewhere you use the word control units and somewhere you use EVMs. We take it, EVMs consist of three parts–ballot unit, the control unit and the VVPAT. All three units should be sealed together. We need clarification on this aspect," the bench told the poll panel.

Senior advocate Santosh Paul, appearing for one of the petitioners, said that source code of EVMs should also be disclosed for transparency.

The bench said, "No, the source code cannot be disclosed as there is a chance of it to be misused." The VVPAT is an independent vote verification system which enables electors to see whether their votes have been cast correctly.

On April 18, the top court reserved its verdict on the batch of pleas.

Underscoring the importance of voter satisfaction and trust in the electoral system, the top court had during the hearing told petitioners, who sought its direction to go back to using ballot papers, not to suspect the efficacy of EVMs and appreciate if the Election Commission does good work.

NGO 'Association for Democratic Reforms' (ADR), one of the petitioners, sought reversal of the poll panel's 2017 decision to replace the transparent glass on VVPAT machines with an opaque glass through which a voter can see the slip only when the light is on for seven seconds.

On April 16, the top court had deprecated criticism of EVMs and calls for reverting to ballot papers, saying the electoral process in India is a "humongous task" and attempts should not be made to "bring down the system".

The seven-phase Lok Sabha polls began on April 19 and the second phase is slated to be held on April 26.

The ADR has sought matching the count in EVMs with votes that have been verifiably "recorded as cast" and to ensure the voter is able to verify through VVPAT slip that his vote, as recorded on the paper slip, has been "counted as recorded".