[fellellor]

I'm guessing you only need to hack one system to throw doubts on the election process, and maybe start some sort of narrative that influences people to vote the other way in the repeat election. Also, the second verification database, mey be needed to be guarded more securely for a longer time in order to give people a chance to verify their votes.

The electronic voting machines are not much different from a paper ballot system in that they are just boxes that hold vote counts, in bits rather than bits of paper. They are not network connected and to my knowledge they are not easily programmable once deployed in the field. i.e, they would require collusion of a large number of local officials, including that of the central election commission officer deployed in order to facilitate reprogramming.

Elections if rigged are done so by people, so the threat comes from the vast numbers of government employees who are deputed from their day jobs to perform election duty. These people hold the power to rig elections by miscounting the paper votes. If the counting process is digitized using dumb machines, then that would maybe take care of the malicious counting problem.

Ultimately any system would rely on the integrity of the actors involved to function properly. In a country with levels of corruption that India faces, it is easier to keep an eye on the few direct employees of the election council rather than every person deputed for election duty.