Most browsers (including mobile ones) except IE support the <keygen> HTML element [1]. This creates a "secure" keypair. The public key can be sent to the server

Most browsers (including mobile ones) except IE support the <keygen> HTML element [1]. This creates a "secure" keypair. The public key can be sent to the server and the private key is stored locally somewhere (I guess gnome-keyring, Mac Keychain or Windows registry). I haven't ever seen this in use except in technical demos. While this can't be used for many things where JS encryption is in use, I'm sure it deserves more recognition than it currently has. [1] https://developer.mozilla.org/En/HTML/Element/keygen https://developer.mozilla.org/En/HTML/Element/keygen