Page "Digital signature" Paragraph 8

In 1976, Whitfield Diffie and Martin Hellman first described the notion of a digital signature scheme, although they only conjectured that such schemes existed.

Soon afterwards, Ronald Rivest, Adi Shamir, and Len Adleman invented the RSA algorithm, which could be used to produce primitive digital signatures ( although only as a proof-of-concept —" plain " RSA signatures are not secure < ref > For example any integer r " signs " m = r < sup > e </ sup > and the product s < sub > 1 </ sub > s < sub > 2 </ sub > of any two valid signatures s < sub > 1 </ sub >, s < sub > 2 </ sub > of m < sub > 1 </ sub >, m < sub > 2 </ sub > is a valid signature of the product m < sub > 1 </ sub > m < sub > 2 </ sub >.</ ref >).

The first widely marketed software package to offer digital signature was Lotus Notes 1. 0, released in 1989, which used the RSA algorithm.