xor

//example
let t='text data',
fx=()=>{
	cont k=0b11111111;
	new Blob([t]).arrayBuffer()
		.then(b=>new Blob([new Int8Array(b).map(y=>y^k).buffer]))
		.then(b=>b.arrayBuffer())
		.then(b=>new Blob([new Int8Array(b).map(y=>y^k).buffer]).text())
		.then(s=>t=s);
	console.log(t);
};
setInterval(fx,50);