Generalized Non-Interactive Oblivious Transfer Using Count-Limited Objects with Applications to Secure Mobile Agents

Oblivious transfer (OT) is a fundamental primitive used in many cryptographic protocols, including general secure function evaluation (SFE) protocols. However, interaction is a primary feature of any OT protocol. In this paper, we show how to remove the interaction requirement in an OT protocol when parties participating in the protocol have access to slightly modified Trusted Platform Modules, as defined by Sarmenta et al.in proposing the notion of count-limited objects (clobs) [8]. Specifically, we construct a new cryptographic primitive called "generalized non-interactive oblivious transfer"(GNIOT). While it is possible to perform GNIOT using clobs in a straightforward manner, with multiple clobs, we show how to perform this efficiently, by using a single clob regardless of the number of values that need to be exchanged in an oblivious manner. Additionally, we provide clear definitions and a formal proof of the security of our construction. We apply this primitive to mobile agent applications and outline a new secure agent protocol called the GTX protocol which provides the same security guarantees as existing agent protocols while removing the need for interaction, thus improving efficiency.