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Despite many advantages of Identity-based Public Key Cryptography (ID-PKC) in removing the certificates of public key over traditional Public Key Infrastructure (PKI), there are some problems related to key escrow property and the need for a secure channel to transmit the private key to the user. A Certificateless Public Key Cryptography (CL-PKC) retains the efficiency of ID-PKC while it solves the key escrow problem and does not need a certificate. The requirement of the infrastructure of the CL-PKC is to transmit the partial key to the user. Therefore, a partial key issuing mechanism is needed to deliver the partial key to the user through a secure channel. In this paper, a new algorithm for partial private key transmission is proposed which uses a simple blinding technique and user chosen secret value to eliminate secure channel problem. The proposed scheme is secure under the hardness assumption of Diffie-Hellman problem. I. INTRODUCTIONOne of the main issues in any systems that generate public and private keys for the user is the binding between public and private keys and the means of verifying these keys. In traditional public key infrastructure (PKI), this is achieved through the use of certificates. In traditional PKI, public and private key can be generated at the same time. Thus, the key pair can be generated by a Certificate Authority (CA) or by user and the integrity of the public key is protected by a certificate issued by the CA. But, one of the difficulties in traditional PKI is certificate revocation. To simplify revocation, Gentry [1] proposed the concept of Certificate-Based Encryption (CBE).According to [1], in CBE, public key generated by a user is authenticated by a certificate issued by CA. A certificate is a digital document signed by CA which binds a public key to a specific user. It provides explicit authentication since the authenticity of the public key can be convinced by anyone verifying the certificate. Any participant who wants to use other entity's public key must first verify the certificate in order to check the authenticity of the public key. So, each user has to retrieve, verify and store the certificates of all users that he is communicating with which requires a large amount of storage and communication and computation. In this model, each entity's private key consist of two components: the first component is a secret or private component that entity choose for itself and keeps it private; and the second component which is issued by CA over a public channel.

As online services increasingly play vital roles in modern society, the possibilities and opportunities offered are limitless, unfortunately, so too are the risks and chances of malicious intrusions. Intrusion Detection Systems (IDSs) has been widely used as an important component in protecting online service towards web attacks and evasions. Yet, today's architectures for intrusion detection force the IDS designer to make a difficult choice to place IDS, so that it can protect itself from a direct attack. To address these challenges, this paper introduces a novel framework to safeguard IDS from a direct attack. Simply called Zero Administrative Server (ZAS), the system incorporates IDS in a Virtual Machine (VM) environment. VM offers strong isolation for IDS from the monitored services and provides significant resistance to malicious attacks. Moreover, this VM based WWW server has the ability to monitor the network traffic to the running services; analyse the information obtained and detect the intrusion; alienate the intruder from the services; and reconstruct the corrupted data or damaged files caused by the evasion. In this paper, we demonstrate ZAS by exposing it to several attacking tools as well as to show the effects it takes on the network performance in terms of TCP throughput and application-to-application round trip time.