Abstract:
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.
