Verifiable Short Signcryption without Random Oracle

Signcryption is a new crypto primitive to model a process achieving privacy and authenticity. Besides privacy and authenticity, non-repudiation is also a pre-requisite property a signcryption for a signcryption scheme. We proposed a publicly verifiable short signcryption scheme which is strong existentially unforgeable under active chosen message attack and is of strong confidentiality under the active chosen cipher-text attack in the flexible unsigncryption oracle. All the security proofs is given standard model without using random oracles.