Efficient fault-tolerant scheme based on the RSA system

Data security on the Internet is an area of considerable concern. A recently proposed fault-tolerant scheme for data encryption that was based on the RSA system is shown to be flawed. The flaw occurs if a malicious receiver keeps a senders message and the corresponding signature and then changes the message whilst retaining the existing signature. Under these circumstances the sender cannot deny having written the forged message since it carries his/her correct signature. An improvement to enhance the security and the performance of the existing RSA-based scheme is presented.