ppap.js

var O = "i have a pen i have an apple apple pen".split("");
var E = "i oari a fib i oari ab affwi affwi-fib".split("");

var code = function(s) {
    return s.charCodeAt(0) - "a".charCodeAt(0);
};
var decode = function(n) {
    return String.fromCharCode(n + "a".charCodeAt(0));
}

for (var i = 0, l = O.length; i < l; i++) {
    var o = O[i];
    var e = E[i];
    if (o == " ") {
        continue;
    }
    var oCode = code(o);
    var eCode = code(e);
    console.log(o, e, oCode, eCode, e == decode((oCode * 2) % 25));

}
/*
i i 8 8 false
h o 7 14 true
a a 0 0 true
v r 21 17 true
e i 4 8 true
a a 0 0 true
p f 15 5 true
e i 4 8 true
n b 13 1 true
i i 8 8 false
h o 7 14 true
a a 0 0 true
v r 21 17 true
e i 4 8 true
a a 0 0 true
n b 13 1 true
a a 0 0 true
p f 15 5 true
p f 15 5 true
l w 11 22 true
e i 4 8 true
a a 0 0 true
p f 15 5 true
p f 15 5 true
l w 11 22 true
e i 4 8 true
p f 15 5 true
e i 4 8 true
n b 13 1 true

*/

What the..