PGP and SSL certificates. These are the names which pop in most heads who have heard the term PKI or public key infrastructure before.

For the last two decades, PKI was kind of equal to RSA. It is a brilliant, easy to understand method for public-key cryptography. Today you can also use elliptic curve cryptography for the same, which offers space savings. For the same level of security it requires smaller key sizes. On the flip side it takes a bit more effort to understand it.

This doesn’t mean RSA would be superseded. It is used more widely than ever. Do you have a government issued ID card? More likely than not, it uses RSA. Do you have credentials for online banking or taxation? The same. Do you have an encryption token from your employer? Ditto. Do you encrypt/sign important emails? Mostly that is done via PGP, which uses RSA.