ICICS 2004

This volume contains the proceedings of the 6th International Conference on Infor- tionandCommunicationsSecurity(ICICS2004), Torremolinos(Malaga), ́ Spain,27-29 October 2004. The ?ve previous conferences were held in Beijing, Sydney, Xian, S- gapore and Huhehaote City, where we had an enthusiastic and well-attended event. The proceedings were released as volumes 1334, 1726, 2229, 2513 and 2836 of the LNCS series of Springer, respectively. During these last years the conference has placed equal emphasis on the theoretical and practical aspects of information and communications security and has established itself as a forum at which academic and industrial people meet and discuss emerging security challenges and solutions. We hope to uphold this tradition by offering you yet another successful meeting with a rich and interesting program. The responseto the Call for Paperswas overwhelming,245 papersubmissionswere received. Therefore, the paper selection process was very competitive and dif?cult - only 42 papers were accepted. The success of the conference depends on the quality of the program. Thus, we are indebted to our Program Committee members and the ext- nal refereesfor the great job they did. These proceedingscontainrevised versionsof the accepted papers.Revisions were not checked and the authorsbear full responsibilityfor the content of their papers.