RSA is a public key (or asymmetric) encryption algorithm, first described publicly in 1977 by Ron Rivest, Adi Shamir and Leonard Adleman at the Massachusetts Institute of Technology (MIT) – the first letters of their surnames make up the name ‘RSA’.

RSA is widely-used today to secure data – for example, in SSH, SSL and TLS protocols and in programs (e.g. browsers) that need to secure data sent over the Internet.