Revolutionizing secure communication, this paper presents a groundbreaking encryption method enabling digital signatures and public-key cryptosystems. Its novel property is publicly revealing an encryption key does not reveal the corresponding decryption key. The method allows secure message encryption using a publicly revealed key, decipherable only by the intended recipient with the corresponding private key. Messages can be "signed" using the private key, verifiable by anyone with the public key, preventing forgery or denial. Encryption involves raising a message representation (M) to a public power (e) and finding the remainder after division by a public product (n) of two large prime numbers (p and q). Decryption uses a different, secret power (d), with security based on the difficulty of factoring n. This breakthrough has transformed electronic communication and data security, with applications in electronic mail and funds transfer. The system's ability to provide both confidentiality and authentication has underpinned the development of modern digital infrastructure and continues to drive innovation in cryptography.
Published in Communications of the ACM, this paper presents a fundamental innovation in computer science, making it highly relevant to the journal's audience. The introduction of public-key cryptography and digital signatures has had a lasting impact on the field and is a landmark contribution to secure communication.