Chapter 9: Sample PT Threat Modeling Document

Every Pluggable Transport should provide a threat modeling document with its source code and binary distributions. This document is necessary to inform developers, auditors and ultimatley users, about what a PT can and cannot do.

****

Sunflower Protocol Disguise System

Sunflower is a Format Transforming Encryption System that disguises traffic as innocuous traffic

Adversary Models:

Threats and Responses:

Threat: Scan for Encrypted Traffic
Threat Description: Adversary tries to determine that encrypted traffic is being transmitted over the internet
Threat Response: System disguises the traffic as other protocol using Format Transforming Encryption
Threat: Scan of Computer ports for Client or Server Listeners
Threat Description: Adversary tries to perform scans of ports on either side to determine what type of service the client and destination
ports are.
Threat Response: System, if a proper connection is not made, returns a message appropriate for a scan of some 'typical' service that may leave an open port
Threat: Deep Packet Inspection performed on Session to search for keywords or signatures in protocols
Threat Description: System utilizes Regex pattern matching to find bad protocol
Threat: Advesary uses targeted blocking
Threat Description: Adversary is performing selective blocking of system.
Threat Response: System has no specific response, other than encryption, to prevent selective blocking.
Threat: Adversary requires password.
Threat