Contributions and Paper Organization. Previous Version.This manuscript is full version of the pa- per presented at IEEE TrustCom, 2018 [16]. The main xxx- xxxxxxxx from the conference version are as follows: Firstly, the list of required security objectives is more comprehen- sive after inclusion of PrFS and KCI resilience. Moreover, the introduction section has been further enhanced by ad- dition of the design principles of the proposed protocols. Furthermore, a new section (Section 4) providing discussion about various aspects of the proposed protocols is also part of this manuscript. This manuscript successfully answers the open question put forward in [16] regarding the feasibility of a privacy-preserving authenticated key agreement proto- col for IEEE Std 802.15.6 offering PrFS and KCI resilience without any dependence on public key cryptography. The second key agreement protocol (termed PPKA2 within this manuscript) is one such protocol satisfying all the requisite security and privacy requirements. Further additional contri- butions of this manuscript are as below: – We enhance our previous analysis [16] of [21] which, in addition to showing that Xx et al.’s scheme does not provide session unlinkability and forward secrecy, also exhibits its vulnerability to KCI attacks. – In addition to the key agreement protocol (PPKA-1) pro- posed in [16], which provided session unlinkability and resolved the privacy flaws found in [21], we present an- other protocol (PPKA-2) that additionally provisions PrFS and KCI resilience. Table 1 lists the security and privacy features provisioned by each protocol. – We develop a formal security and privacy model in an appropriate complexity-theoretic framework and prove the proposed protocols secure in this model. Table 1: Comparison of Security and Privacy Features Security/Privacy Feature Xx et al. PPKA-1 PPKA-2 PrFS C C ✓ KCI Resilience C C ✓ Session Unlinkability C ✓ ✓ Anonymity ✓ ✓ ✓ The remainder of this paper is organized as follows: – Section 2, provides an overview and analysis of a WBAN key agreement scheme proposed in [21]. – The proposed protocols are detailed in Section 3. – Section 4 discusses pertinent aspects of the proposed protocols. – Sections 5 and 6 explain the formal security model and the associated analysis, respectively. Table 2: Notations used in [21] Symbol h(.) (a, b) S⊕A N HN IN idN idI′N tidN kHN kN, fN rN aN, bN xN, xX x, x, x, x xX xX X →Y : Z Description Cryptographic hash function Concatenation of a and b Bitwise XOR operatio...
Contributions and Paper Organization. First, in Section 1 we provide a brief overview of agreement tasks and stabilizing tasks in general. We also describe our main contributions and overall paper structure while also referencing and showcasing some of the relevant existing related work. In Section 2 we provide a precise computational model for processes as well as the general setting for Message Adversaries in the synchronous message passing system. In this section we also include the model for Broadcastable Asynchronous Message Passing. In Section 3 we briefly recall the Min-Max algorithms introduced by Xxxxxxx-Xxxx and Xxxxx, and we also introduce some original definitions that will be necessary for stating the main results. Stabilizing Agreement is Impossible in Delayed Message Passing Models We also provide a Min-Max algorithm extension that allows stabilizing agreement to be solved whenever the dynamic diameter is functionally-bounded. In Section 4 we establish our main results, namely, the stabilizing agreement impossibility for the Delayed Lossy-Link model, and the equivalence between terminating tasks in the Lossy-Link model, and the Delayed Lossy-Link model. We also show that the Delayed Lossy-Link model is equivalent to the Broadcastable Asynchronous Message Passing model with 2 processes. Finally in Section 6 we revisit our main results and formulate some corresponding insights re- xxxxxxx stabilizing tasks, termination and synchrony. We also list some research directions and open questions that we consider that might be interesting to focus on future related work.
