Actually we need something much stronger. We need two copies of a voter verified paper ballot. One that is kept by the board of elections, and one that is kept by the voter. Both have the same serial number which can not be traced to the voter by the government, but which the voter can use to determine that his vote was counted accurately.
Board of elections paper ballots are kept & are the only acceptable method for recounts. Voter copies are the property of the voter and the government must publish on the web a voter searchable database of how each ballot was counted.
This allows the voter to go home & check that his/her vote was counted properly, and gives a record which can be used in later proceedings to correct improperly recorded votes.
Couple this with some real penalties for election fraud and the system may work pretty well.
Give the voter a point-of-voting receipt (exactly like a VISA card receipt), spit the other, presumably carbonless, copy into a bin below the booth (locked, of course), and Bob's your uncle. Simplest thing in the world for maintaining integrity. But, we DO want a stroke/click/touch log, too -- mostly for determining malfunction, but also to catch out certain types of fraud that might be inserted into the control software.
Now, just WHO do you think DOESN'T want these safeguards? Uh huh. Right first time.
FReegards!