Signcryption
In cryptography Signcryption indicates an asymmetric crypto system, which can ensure authenticity and confidentiality of a message simultaneously. Signcryption implementations require significantly less computation and communication volume than conventional methods, which sign to ensure the authenticity and confidentiality of the message first and then symmetrically encrypt ( Sign -then- Encrypt ) for certain applications (especially for large key lengths ). The efficiency benefits of Signcryption ( a) require that all parties share the common key parameters and ( b ) require the interaction of the signature receiver ( Bob ) and the crucial third party ( judge ) in a dispute over the validity of a signature (Interactive repudiation Settlement ).
Signcryption was first published in 1997 and is in Australia and the United States patented ( Australia: Patent No. 721 497, USA: Patent No. 6,396,928 ).