International Journal of Emerging Technology and Advanced Engineering Website: www.ijetae.com (ISSN 2250-2459, Volume 2, Issue 9, September 2012) 104 Authentication of Medical Images using Integer Wavelet Transforms A.Kannammal 1 , Dr.S.Subha Rani 2 1 Assistant professor, 2 Professor and Head, ECE Department, PSG College of Technology, Peelamedu, Coimbatore Abstract - In these days, medical image exchanges between hospitals have become a vital technique as a result of the development of the latest technology in communications and computer networks. A new fragile watermarking algorithm for medical images using selective bit plane of integer wavelet transform domain is proposed and implemented. This algorithm makes it possible to resolve the security and forgery problem of the medical images. For the selection of insertion planes, n random numbers are generated, which have the integer value from 1 to 8, and the required plane is selected using the key.MSB Values are given as input to obtain the hash value. The output of the hash function is embedded into the selected plane, and it is combined with the MSBs to get the watermarked coefficients. The experimental results show a very good improvement in image quality in terms of PSNR compared to Reversible watermarking technique using Hash algorithm. This Algorithm shows an excellent Tamper detection capability and shows the exact location of the tamper. In addition, by using integer wavelet transform, this algorithm can utilize Hash function and improves the security of the inserted watermark. Keywords - Discrete wavelet Transforms, DICOM, fragile watermark, PSNR I. INTRODUCTION Biomedical image security is an important field of research in medical informatics, which is continuously growing. The increasing adoption of information systems in healthcare has led to a scenario where patient information security is more and more being regarded as a critical issue. Allowing patient information to be in jeopardy may lead to irreparable damage, physically, morally, and socially to the patient, potentially shaking the credibility of the healthcare institution. Medical images play a crucial role in such context, given their importance in diagnosis, treatment, and research. Therefore, it is vital to take measures in order to prevent tampering and determine their provenance. This demands adoption of security mechanisms to assure information integrity and authenticity. However, the security problems have emerged seriously in network transferred medical image Tampering medical image may cause serious results in medical treatments. With this reason, preventing medical image from forgery becomes very important, and a digital watermarking technique can be a solution in resolving such a problem. This shows that the demand for medical image authentication have become enormous. II. METHODOLOGY A new fragile watermarking algorithm for medical images is proposed. This algorithm makes it possible to resolve the security and forgery problem of the medical images. Instead of the discrete wavelet transform, an integer wavelet transform is used to utilize hash function. The watermark associated with the hash values is inserted into the LSBs of the integer wavelet transform coefficients. This algorithm also detects a forged area of the image very well. The conventional fragile watermarking methods have handled a watermark for image; Most of them insert the watermark into the LSBs of cover image. In this case, they have a problem that the watermark can be removed easily by modifying LSBs. To overcome such a problem, a new fragile watermarking algorithm using selective bit plane mechanism is proposed .The proposed algorithm uses bit plane schema in integer wavelet transform domain and solves the LSB inserting problem, which is used in conventional fragile watermarking techniques. In this technique, the inserted bit plane is selected randomly with a key. It also utilizes integer wavelet transform domain instead of spatial one. One advantage of using an integer wavelet transform is that the transformed coefficients are integers, which can be used in a hash function. An integer wavelet transform is used in this algorithm instead of discrete wavelet transform because the Hash function can encode integer values only. The coefficients of discrete wavelet transform are not integers, and the coefficients have to be changed into integers in order to utilize hash function. Making the coefficients integers by converting the real values may cause error when the inverse transform is performed. On the other way, the coefficients of integer discrete wavelet transform are integers, and these coefficients can be used in hash function encoding directly without any problems. This also makes it easier in getting a digital signature.