BOUSLIMI Dalel^1,2, COATRIEUX Gouenou^1,2, ROUX Christian²

Article de revue avec comité de lecture

Computer methods and programs in biomedicine, november 2011

2011

In this paper we propose a joint encryption/watermarking algorithm for the purpose of protecting medical images. The proposed solution gives access to the outcomes of the image integrity and of its origins as its attachment to one patient even if the image is stored encrypted. In this study, the given solution combines the RC4 stream cipher and two substitutive watermarking modulations: the Least Significant Bit Method and the Quantization Index Modulation. If watermarking and encryption are conducted jointly at the protection stage, watermark extraction and decryption can be applied independently. Experimental results achieved on 8bits encoded echographic images illustrate the overall performances of the proposed scheme. At least, a capacity rate of 1 and 0.5bits of message per pixel of image can be embedded in the spatial and the encrypted domains respectively, with a peak signal to noise ratio greater than 49dB.

1 : ITI - Dépt. Image et Traitement Information (Institut Mines-Télécom-Télécom Bretagne-UEB)
2 : LATIM - Laboratoire de traitement de l'information médicale (Institut Mines-Télécom-Télécom Bretagne-UEB/ INSERM/CNRS UMR 1101)

Medical image security, Watermarking, Quantization index modulation, Stream cipher

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