[Karunamon]

I was quite surprised how much text you can fit into a single QR code nowadays. 2778 bytes of lorem ipsum generates a massive code (1000x1000), but it can still be read passively with an iPhone's camera. For comparison, a Google CA cert is only 1363 bytes. You could theoretically dump your cert and private key onto their own (big) single page codes, then just scan them back in when you later need it. That just leaves the possibility of your printer holding onto something it shouldn't.