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 sender´s message and corresponding signature, 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 performance of the existing RSA-based scheme is presented.