This volume contains the papers presented at the 15th International Conference on Logic for Programming, Arti?cial Intelligence, and Reasoning (LPAR) held November22-27inDoha, QataronthepremisesoftheQatarcampusofCarnegie Mellon University. In its 15th edition, LPAR looked back at a rich history. The conference evolved out of the First and Second Russian Conferences on Logic Progr- ming, held in Irkutsk, in 1990, and aboard the ship "Michail Lomonosov" in 1991. The idea of organizing the conference came largely from Robert Kowalski, who also proposed the creation of the Russian Association for Logic Progr- ming. In 1992, it was decided to extend the scope of the conference. Due to considerableinterestinautomatedreasoningintheformerSovietUnion, thec- ference was renamed Logic Programming and Automated Reasoning (LPAR). Under this name three meetings were held during 1992-1994: again on board the ship "Michail Lomonosov" (1992), in St. Petersburg, Russia (1993), and on board the ship "Marshal Koshevoi" (1994). In 1999, the conference was held in Tbilisi, Georgia. At the suggestion of Michel Parigot, the conference changed its nameagaintoLogicforProgrammingandAutomatedReasoning(preservingthe acronym LPAR ) re?ecting an interest in additional areas of logic. LPAR 2000 was held on Reunion Island, France. In 2001, the name (but not the acronym) changed again to its current form. The 8th to the 14th meetings were held in the following locations: Havana, Cuba (2001) Tbilisi, Georgia (2002); Almaty, Kazakhstan(2003);Montevideo, Uruguay(2004);MontegoBay, Jamaica(2005); Phnom Penh, Cambodia (2006); and Yerevan, Armenia (2007).

This book constitutes the refereed proceedings of the 12th Asian Computing Science Conference, ASIAN 2007, held in Doha, Qatar, in December 2007.

The 15 revised full papers and 10 revised short papers presented together with 3 invited lectures were carefully reviewed and selected from 112 submissions. Covering all current aspects of computer and network security, the papers are organized in topical sections on program security, computer security, access control, protocols, intrusion detection, network security, and safe execution.