Agreed. There are a couple of other papers as well.
The problem is they are far too complicated to explain to voters which makes them unlikely to be adopted and unlikely to be trusted. Having a secure vote is obviously the primary goal, but having a vote that people trust is pretty important too.
They're not necessarily so complicated. For example: you get a receipt, check it, and put it in a box. Another voter takes it home and can validate it against the official count.
This system was designed by a couple cryptographers, one of them Ron Rivest of RSA fame. For details on this and a couple other simple voting systems, see here:
http://rangevoting.org/RivSmiPRshort.html
The problem is they are far too complicated to explain to voters which makes them unlikely to be adopted and unlikely to be trusted. Having a secure vote is obviously the primary goal, but having a vote that people trust is pretty important too.