my aim is to create a self ink electronical stamp to use in elections. hash code of stamp will be put on the paper. Then the hash code can be validated in a web page. basicly there are self ink auto increment stamps. http://www.staples.com/self+inking+date+and+time+stamp/directory_self+inking+date+and+time+stamp
but my aim is to use encryption to embded the time and day to a hashcode. then the voter press the bunnon time will be printed on the ballot.