Cryptography · 1978 · Ronald L. Rivest, Adi Shamir & Leonard M. Adleman
A Method for Obtaining Digital Signatures and Public-Key Cryptosystems
Construct public-key encryption and signatures from modular exponentiation and a trapdoor tied to the difficulty of factoring.
The central move
Construct public-key encryption and signatures from modular exponentiation and a trapdoor tied to the difficulty of factoring.
Why it had to exist
Diffie and Hellman described the possibility of public-key systems but did not provide this general-purpose construction. A concrete reversible asymmetry was needed.
Where it leads
Trapdoor permutation → signatures and key transport → PKI, software provenance, and authenticated protocols.