ID based public key cryptosystems based on Okamoto and Tanaka's ID based one way communication scheme
Y.-W. Tsai, Tzonelih Hwang · Electronics Letters · 1990
With a slight modification to Okamoto and Tanaka's ID-based one-way communication scheme, two identity-based public-key cryptosystems are proposed. These systems do not possess the conspiracy problem and can withstand certain key attacks common to most public-key cryptosystems.