'Digital Signature and Blocking in Mobile Ambients'
Authors
Palit, Anupam ; Ren, Bin ; Bingi, Sagar ; Sun, Yepeng
Term
10. Term
Education
Publication year
2006
Abstract
Mobile Ambients er en formel model, afledt af pi‑kalkylen (en matematisk ramme for samtidige processer), der beskriver hvordan mobile softwareagenter interagerer i afgrænsede rum kaldet ambients. Hvert ambient rummer lokale agenter og kan indeholde subambients; ambients kan flyttes som hele enheder, mens agenterne er begrænset til deres eget ambient. Denne afhandling præsenterer en sikker variant af Mobile Ambients. For at håndtere robusthed mod ondsindet manipulation, adgangskontrol og sikker eksekvering udstyres ambients med digitale signaturer (til at autentificere kode og handlinger) og blokering af capabilities (til at forhindre uautoriserede operationer). Den resulterende model, Digitally Signed Ambients with Blocking on Capabilities (DSABC), ligger i tråd med sandboxing‑tilgange som i Java 2 (JDK 2.0) og Umbrella‑projektet for Linux‑sikkerhed. Med udgangspunkt i denne kalkyle introduceres et typesystem, der beskriver forskellige sikkerhedspolitikker og understøtter ræsonnement om, hvilke handlinger der er tilladt i modellen. Samlet viser arbejdet, hvordan formelle mobilitetsmodeller kan udbygges med praktiske sikkerhedsmekanismer uden at ændre deres grundstruktur.
Mobile Ambients is a formal model, derived from the pi‑calculus (a mathematical framework for concurrent processes), for describing how mobile software agents interact inside bounded compartments called ambients. Each ambient contains local agents and can nest subambients; ambients can move as whole units, while agents are confined to their own ambient. This thesis presents a secure variant of Mobile Ambients. To address robustness against malicious tampering, access control, and safe execution, it equips ambients with digital signatures (to authenticate code and actions) and blocking on capabilities (to prevent untrusted operations). The resulting model, Digitally Signed Ambients with Blocking on Capabilities (DSABC), follows the same spirit as sandboxing approaches seen in Java 2 (JDK 2.0) and the Umbrella project for Linux security. Building on this calculus, the thesis introduces a type system that captures different security policies and supports reasoning about which actions are permitted within the model. Overall, the work shows how formal models of mobility can be extended with practical security mechanisms without changing their core structure.
[This abstract was generated with the help of AI]
Documents