I am talking about the usefulness of security theater on the margins. At a concert venue, and at a polling place, we can do things that, in the abstract, increase security, but provide little to no actual benefit and actually serve to make the process more difficult and unpleasant on the whole.

(Ignoring RSA tangent, making all concert-goers go through an X-Ray to screen for weapons and drugs would catch more weapons and drugs than the current pat down/bag check process does. It would undeniably increase the security of the venue, while slowing down entry, exposing concertgoers to X-Rays, and IMO providing more annoyance than actual extra security)

It seems that you think, for voting, that's a fine trade-off. I do not.

edit: not disagreeing that signed tickets would prevent fraud. Disagreeing that it would be worth, say, an additional $5 fee on the tickets, plus slower more expensive readers to verify that they're signed correctly, plus plus plus etc etc. My entire argument here is based on the net utility of additional security measures, not whether or not those measures provide additional security.