New Hybrid Signcryption Approach: Efficient Digital Envelope Signcryption

In the study of Cryptography, the most important and widely studied are confidentiality and integrity. Confidentiality is supported by encryption schemes, while integrity is provided by digital signature schemes. Drawback of symmetric encryption is key distribution problem. Although asymmetric encryption can solve this problem, all of these ciphers are hundreds or thousands of times slower than symmetric ciphers. Digital envelope combines the advantages of asymmetric and symmetric key ciphers. It eliminates time complexity problem of asymmetric encryption and key exchange problem of symmetric encryption. But it cannot provide data integrity. So it cannot be avoidable to use digital signature scheme to guarantee the source and integrity. New hybrid signcryption approach named “Efficient Digital Envelope Signcryption” is proposed. This new approach operates digital signature process and asymmetric encryption process in a single step. It takes advantages of digital envelope scheme and signcryption scheme with appropriate algorithms