Usability. One time pads have been around forever, are provably secure, but a pain in the ass.
Modern symmetric ciphers solve the "you need to securely exchange as much key material as you wish to send data" using mathematical formulas to stretch key material. Asymmetric ciphers use mathematical formulas to fix "you need a secure way to exchange keys."
Unfortunately, the math can't be probably secure, only believed secure and proved insecure.
Modern symmetric ciphers solve the "you need to securely exchange as much key material as you wish to send data" using mathematical formulas to stretch key material. Asymmetric ciphers use mathematical formulas to fix "you need a secure way to exchange keys."
Unfortunately, the math can't be probably secure, only believed secure and proved insecure.