> It's kinda surprising that symmetric-key algorithms have been so resistant to attacks. One reason is public-key cryptography is tremendously hard to get righ

> It's kinda surprising that symmetric-key algorithms have been so resistant to attacks. One reason is public-key cryptography is tremendously hard to get right. PGP as a case-in-point. Signal and Keybase tried to replace and extend PGP respectively with some success, so it could be done. Just that, it demands a lot of discipline. > Where is symmetric key cryptography used for nowadays in normal applications programming? As two examples: TLS, after the PKI-dependant key exchange, goes symmetrical (the same holds true for Signal and Keybase but not for PGP). Next, most server-side data encryption schemes are reliant on symmetric cryptography, as well.