This year the 4th WSEAS International Conference on COMPUTER ENGINEERING and APPLICATIONS (CEA '10) was held at Harvard University, Cambridge, USA, January 27-29, 2010. The conference remains faithful to its original idea of providing a platform to discuss network architecture, network design software, mobile networks and mobile services, digital broadcasting, e-commerce, optical networks, hacking, trojian horses, viruses, worms, spam, information security, standards of information security: aes, ipsec, high-tech crime prevention, real-time operating systems, hardware engineering, supercomputing, artificial intelligence, microprocessors, microcomputers, antennas and radars, lightwave technology, numerical methods for electromagnetics, aerospace systems, atm networks, military communications, cyber-science and cyber-space, mathematical logic and computers, image, video and internet technologies, web-based education, law aspects related to informatics etc. with participants from all over the world, both from academia and from industry.