Actually, even without printer, the only way for fraud is if Santa Claus came flying and magically changed all the votes. The candidates and their agents would have to be duffers to not notice Santa Claus, no?
Sir, the problem with electronic voting is that fraud can be done behind closed doors (by replacing components etc in the machine) and such fraud would be much more difficult to detect. So electronic voting by itself is not secure. Past experience (booth capturing, ballot box stuffing, etc) has shown that paper voting by itself is also not secure.
However, IMHO, a combination of both electronic+paper voting is significantly more secure than either electronic voting by itself or paper voting by itself. I see such a combination working as follows:
1. A voter will cast his vote electronically.
2. Electronic voting machine prints out the vote on a paper
3. Voter presses a button on the electronic machine to confirm that paper vote is correct, so that the electronic machine can record the vote.
4. The voter folds the paper to hide the vote (there are visual security marks printed on other side of the paper).
5. The voting official then visually inspects the folded paper to make sure that the paper has indeed been printed out of the machine.
6. The voter deposits the paper vote in ballot box in sight of the voting official.
7. Voting is complete at this point and election official presses a button on control unit to tell the voting machine to "lock" the electronic vote.
8. Control unit prints out a receipt that is handed to the voter
If for some reason, the voter fails to deposit paper in the ballot fox, the election official will not press the button to "lock" the electronic vote and the final paper receipt that is given to the voter indicates that his/her vote was properly recorded.
Now, we have two independent
sources of truth, one electronic and one paper. These two sources of truth must now be handled completely separate and independent of each other. Electronic votes will be counted electronically by a group of people; while as, paper votes will be counted manually (without using any machines) by a different group of people.
Electronic and paper votes can then be correlated and the following things can happen:
1. Electronic and paper result perfectly match - good outcome.
2. Too many "unlocked" electronic votes - someone was trying to disrupt the voting process so that revoting will happen.
3. Significant deviation between electronic and paper votes - Fraud going on
- checking security mark behind paper vote will reveal whether the fraud is electronic or paper.
4. Minor deviations in result as a result of some problem in voting process
- for the first time in history we will know how flawed or good the voting process is and this deviation can be reduced over time by EC.
EVM's can print multiple copies of vote on paper containing (in text) Time, Unique ID, party voted for and same data within a QR code.
Election Commission keep one copy, give other copy to voter and may be even to Political Parties and independent observers.
All (EC-Voters-Parties-Observers) can easily scan these QR codes(possible with most new phones) and compare when need arises.
How hard is that ?
The system must be kept as simple as possible. The simpler the system, the easier it is to ensure that it is secure. Also, the whole point of paper vote IMHO is to provide an alternate source of truth which is machine independent, so as far as I can see its good to include security marks on the ballot paper, but all counting of paper votes MUST be 100% manual without any machine intervention - right down to making sure that the final paper results are displayed on a blackboard with hand written numbers - no machine intervention what so ever - otherwise what's the point of maintaining a separate paper trail?