Protocol Derivation Assistant Matthias Anlauff Kestrel Institute

Outline Motivation Architecture –Overview –Components Basic Functionality Future Directions

Motivation Provide a support tool for the Protocol Composition Logic [Pavlovic et.al.]: –Specification of protocols (strands, pomsets) –Protocol derivations using composition and refinement –Verification and validation of security properties –Interfacing with other security protocol tools/languages

PDA Architecture - Overview Protocol Derivation Engine Syntax Checker Protocol Instance Engine Protocol Composition & Refinement Engine Protocol Library Manager Code Generator Graphical User Interface Graphical Editor Derivation Browser

Pda Graphical User Interface Graphical editor (nodes+edges) Nested nodes with graphical expand/collapse functionality All entities in a protocol derivation are defined using the graphical user interface (Protocols, Constructors, Derivations) basic definition of a protocol

Protocol Derivations: Instances Protocols can be generated from existing one by using instantiations Pda provides the functionality to –(graphically) create instances of protocols –check instance relation between protocols creating a protocol as an instance of another one

Derivation Browser The derivation browser visualizes the relationship between protocols (e.g., “instance-of” relations) The derivation browser shows relations across file borders “Working Sets” can be used to restrict the scope of the derivation browser. Derivation browser functionality

Protocol Derivation: Constructors Constructors can be used to define composition and/or refinement operations on protocols The protocols are composed/refined on the basis of their signature information Internal checks ensure that a constructor can only be applied to protocols that are instances of the constructor parameters Definition and applications of a constructor

Protocol Derivation: Rules Pda Rules are similar to constructors; they can be used to define schemas for the composition and/or refinement of protocols Rule applications use the process information of the argument protocols rather than the internal signature representation Definition and applications of a rule

Protocol Library Support An import/export functionality is provided in order to allow users to easily exchange and update protocol derivation files Currently this functionality is file-based; future versions will be able to import protocol derivation files directly from the Web

Code Generation The code generator translated protocols and/or protocol derivations into source code Pda will provide an extension interface for connecting customized code generators (C++, Java, Model-Checker, etc.)

PDA – Current status Graphical support tool for the protocol derivation logic Supports defining protocol templates, instantiations, and generating protocols with user-defined, constructors and rules Browsing of protocol derivations using instance/derivation information

Future Directions Hook up with theorem provers/ model checkers –Either existing or customized ones Generalize component code generation –Target different programming/spec languages –Generate traces, instrumentations, sanity checks