Too many people worry about tampering of EVM's. Anything can be tampered with, however what is more important is the chain of custody. The EVM's are open to checking by all political parties and agents of all political parties can keep a watch on the elctoral process. Once sealed & taken to a secure location, agents can keep a watch on the buiulding concerned from outside & make sure there is abolutely no one entering & tampering. That can also be done by adding cctv's to keep a watch in real time. Again the EVM's are unsealed in the presence of all the agents & then counting is done . As best a system for countries like India, Pakistan & the like....