function verify(string sha256) constant returns (string) {
    var timestamp =  proofs[sha256];
    if ( timestamp == 0 ){
        return "No data found";
    }else{
        DateTime dt = DateTime(msg.sender);
        
        uint year = dt.getYear(timestamp);
        uint month = dt.getMonth(timestamp);
        uint day = dt.getDay(timestamp);
        uint hour = dt.getHour(timestamp);
        uint minute = dt.getMinute(timestamp);
        uint second = dt.getSecond(timestamp);
        
        result = strConcat(uintToString(year) , "-" , uintToString(month),"-",uintToString(day));
        result = strConcat(result," ");
        result = strConcat( uintToString(hour) , ":" , uintToString(minute),":",uintToString(second));
        result = strConcat(result," UTC");
        


        

        return result;
    }
  }