The 4th International Conference on Security in Communication Networks 2004 (SCN2004)washeldatthe DioceseHall oftheArchdioceseofAmal?-Cavade Tirreni and the Armorial Bearings Hall of the Archbishop Palace in Amal?, Italy, on September 8 10, 2004. Previous conferences also took place in Amal? in 1996, 1999 and 2002. The conference aimed at bringing together researchers in the ?elds of cr- tography and security in communication networks to foster cooperation and the exchange of ideas. The main topics included all technical aspects of data security, including: anonymity, authentication, blockciphers, complexity-basedcryptography, cry- analysis, digital signatures, distributed cryptography, hash functions, identi?- tion, implementations, keydistribution, privacy, publickeyencryption, threshold cryptography, and zero knowledge. The Program Committee, consisting of 21 members, considered 79 papers and selected 26 for presentation; one of them was withdrawn by the authors. These papers were selected on the basis of originality, quality and relevance to cryptography and security in communication networks. Due to the high number of submissions, paper selection was a di?cult and challenging task, and many good submissions had to be rejected. Each subm- sion was refereed by at least three reviewers and some had four reports or more. We are very grateful to all the program committee members, who devoted much e?ort and valuable time to read and select the papers. In addition, we gratefully acknowledge the help of colleagues who reviewed submissions in their areas of expertise. They are all listed on page VII and we apologize for any inadvertent omissions. These proceedings include the revised versions of the 26 accepted papers andtheabstractoftheinvitedtalkbyBartPreneel(ECRYPT: theCryptographic Research Challenges for the Next Decade)."

The Eighth Italian Conference on Theoretical Computer Science (ICTCS 2003) was held at the University Residential Center of Bertinoro, Italy, on October 13-15 2003. The center is composed of three large historical and monumental buildings not far from one another, forming a united complex on the top of the built up area of the ancient town of Bertinoro. Previous conferences took place in Pisa (1972), Mantova (1974 and 1989), L'Aquila (1992), Ravello (1995), Prato (1998), and Torino (2001). The conference aims at bringing together computer scientists, expecially youngresearchers, tofostercooperationandexchangeideasandresults.Itsmain topicsinclude: analysisanddesignofalgorithms, datatypesanddatastructures, theory of logical design and layout, computability, complexity, automata, s- bolic and algebraic computation, security, cryptography, speci?cation and ve- ?cation, formal languages, foundations of functional programming, foundations of logic programming, term-rewriting, semantics, type theory, new computing paradigms, parallel and distributed computation, theory of concurrency, theory of databases, theory of knowledge bases, theory of robotics. The program committee, consisting of 14 members, considered 65 papers and selected 27 for presentation. These papers were selected on the basis of origin- ity, quality, and relevance to theoretical computer science. These proceedings include the revised versions of the 27 accepted papers and the invited talks by Marios Mavronicolas (Extreme Nash Equilibria), Martin Hofmann (Certi?cation of Memory Usage), and G erard Boudol (On Programming Models for Mobility)."