A robust encryption and digital watermarking scheme for dicom images using quaternions and DWT-SVD

The Digital Image and Communication On Medicine (DICOM) images are now subjected for transmission over the internet which bring about concerns regarding data security. The security of the medical images over the DICOM network currently relies on encryption techniques such as Advanced Encryption Standard (AES) and Triple Data Encryption Standard (3DES). These techniques however consume substantial processing time for the medical images. A new lossless encryption technique using quaternions can be adopted which reduces the processing time enormously. The quaternion technique is implemented using counter mode of encryption and modular arithmetic operations. The security of the medical image transmission can even be enhanced by incorporating digital watermarking which serves as an authentication of the sender and also reduces the difficulty in maintenance of multiple documents. The signature of the patient and the patient data are used as the watermark images and they are embedded in the DICOM image using DWT-SVD (Digital Wavelet Transform- Singular Value Decomposition).