One of the primary mechanisms against voter fraud, is compulsory voting.
If every voter is required to vote - there is no scope for additional fraudulent votes.
Any fraudulent vote sticks out immediately - as it doubles up with a legitimate vote, which is then investigated.
You can only have fraudulent votes in a system based on many voters, not voting at all - once that is the system, there is the opportunity to "activate" the latent votes fraudulently.
Compulsory universal voting, is democratically superior, on principle, and eliminates 99% of fraud opportunities, making mechanisms such as ID, redundant.
Where the voting is NOT compulsory and universal - then mechanisms such as ID become necessary... along with their entire, expensive, and painful, bureaucracy.
I always find it remarkable that the very same people who are proponents of small government, elimination of regulation, etc... are frequently the leaders in the charge for voter ID - ie: more regulation and bureaucratic red tape!!!
You want to simplify and make the system more reliable - make it compulsory and universal - less scope for gaming the system, greater ability to identify any attempt to game the system, and reduced bureaucracy/regulation. win-win-win.