Patent ID: 7424114
Filing Date: 2008-09-09
Classification: H04L

Abstract:
1. A public key encryption method comprising the following steps: a) generating a random number r, b) Applying a hash function F to a message M and to the random number r in order to obtain a first bit string s; c) Applying a hash function H to s and performing an Exclusive OR of the result with r in order to obtain a second bit string t; d) Defining an intermediate message w=s∥t, where ∥ denotes the concatenation of two bit strings; e) Applying a public key probabilistic encryption algorithm EP to the intermediate message w and to a random number u in order to obtain a first encrypted item c1, using a public key pk; f) Applying a hash function G to w and c1 in order to obtain a key k; g) Applying a secret key encryption algorithm ES to the message M using the key k in order to obtain a second encrypted item c2; and h) Generating the encrypted message C=c1∥c2.