Group Time-based One-time Passwords and its Application to Efficient Privacy-Preserving Proof of Location

Abstract

Time-based One-Time Password (TOTP) provides a strong second factor for user authentication. In TOTP, a prover authenticates to a verifier by using the current time and a secret key to generate an authentication token (or password) which is valid for a short time period. Our goal is to extend TOTP to the group setting, and to provide both authentication and privacy. To this end, we introduce a new authentication scheme, called Group TOTP (GTOTP), that allows the prover to prove that it is a member of an authenticated group without revealing its identity. We propose a novel construction that transforms any asymmetric TOTP scheme into a GTOTP scheme. Our approach combines Merkle tree and Bloom filter to reduce the verifier's states to constant sizes.As a promising application of GTOTP, we show that GTOTP can be used to construct an efficient privacy-preserving Proof of Location (PoL) scheme. We utilize a commitment protocol, a privacypreserving location proximity scheme, and our GTOTP scheme to build the PoL scheme, in which GTOTP is used not only for user authentication but also as a tool to glue up other building blocks. In the PoL scheme, with the help of some witnesses, a user can prove its location to a verifier, while ensuring the identity and location privacy of both the prover and witnesses. Our PoL scheme outperforms the alternatives based on group digital signatures. We evaluate our schemes on Raspberry Pi hardware, and demonstrate that they achieve practical performance. In particular, the password generation and verification time are in the order of microseconds

Composable Anonymous Proof-of-Location With User-Controlled Offline Access

“…For instance, initiating the POL protocol might require the user to input a password or provide a scan of biometric data (e.g., face) to the device. Similar assumptions are commonly made in credential systems [18], [21], [22] and POL systems [2], [4], [29], [30]. In the work presented by Kounas et al [31], a video challenge and response mechanism for verifying strong identity, along with a simple timeout-based device location verification, are proposed.…”

“…Proof-of-location systems have been widely studied [2], [3], [4], [5], [6], [7], [8], [10], [13], [29], [30]. Lack of formal security model has led to attacks on POL systems, for example, absence of the message travel time measurements makes POL in [6] and [31] vulnerable to relay attacks.…”

“…User anonymity is considered in [5], [8], [29], [30], and [31]. [29], [30] only provide anonymity against the verifier, and do not have formal security models.…”

“…User anonymity is considered in [5], [8], [29], [30], and [31]. [29], [30] only provide anonymity against the verifier, and do not have formal security models. As in our work, pseudonyms have been used to provide user anonymity in [5], [8], and [31].…”

HMACCE: Establishing Authenticated and Confidential Channel From Historical Data for Industrial Internet of Things

“…We say that an HMACCE protocol is (t, , q l , MN)-secure, if there exists no PPT adversary that (t, , q l , MN)-breaks it. [38], [4], [39].…”