Fujisaki-Okamoto IND-CCA hybrid encryption revisited.
David Galindo, Sebastià Martín Mollevi, Paz Morillo, Jorge Luis Villar · 2003
At Crypto'99, Fujisaki and Okamoto [10] presented a nice generic transformation from weak asymmetric and symmetric schemes into an IND-CCA hybrid encryption scheme in the Random Oracle Model. From this transformation, two specific candidates to standardization were designed: EPOC-2 [9] and PSEC2 [16], based on Okamoto-Uchiyama and El Gamal primitives, respectively. Since then, several cryptanalysis of EPOC have been published, one in the Chosen Ciphertext Attack game and others making use of a poor implementation that is vulnerable to reject timing attacks.