[2]  M. Yeung and F. Mintzer, An invisible watermarking technique for image verification," in  IEEE International Conference on Image Pro- cessing, vol. 2, 1997, pp. 680 { 683. [3]  M. Wu and B. Liu, Watermarking for image authentication," in IEEE International Conference on Image Processing, vol. 2, 1998, pp. 437{ 441. [4]  J. Fridrich, M. Goljan, and A. C. Baldoza, New fragile authentication watermark for images," in  IEEE International Conference on Image Processing, Vancouver, Canada, 2000. [5]  P. W. Wong, A watermark for image integrity and ownership verifi- cation," in IS&T Conference on Image Processing, Image Quality and Image Capture Systems, Portland, Oregon, 1998. [6]  E. T. Lin, C. I. Podilchuk, and E. J. Delp, Detection of image al- terations using semi-fragile watermarks," in  SPIE International Con- ference on Security and Watermarking of Multimedia Contents II, vol. 3971, San Jose, CA, 2000. [7]  C.-Y. Lin and S.-F. Chang, A robust image authentication method surviving jpeg lossy compression," in SPIE Storage and Retrieval of Im- age/Video Database, ser. IS&T/SPIE Symposium on Electronic Imag- ing: Science and Technology, San Jose, 1998. [8]  J. Fridrich, Image watermarking for tamper detection," in  IEEE In- ternational Conference on Image Processing, Chicago, 1998. [9]  N. Memon and P. Vora, Authentication techniques for multimedia content," in SPIE Multimedia Systems and Applications, Boston, MA, 1998. [10]  C.-Y. Lin and S.-F. Chang, A robust image authentication method distinguishing jpeg compression from malicious manipulation,"  IEEE Transactions on Circuits and Systems for Video Technology, 2000. [11]  M. Schneider and S.-F. Chang, A robust content based digital signa- ture for image authentication," in  IEEE International Conference on Image Processing, vol. 3, Lausanne, Switzerland, 1996, pp. 227{230. [12]  S. Bhattacharjee, Compression tolerant image authentication," in IEEE International Conference on Image Processing, Chicago, 1998. 22