Introduction Present HRP ranging-capable devices (RDEVs) use the content of the SHR to estimate time of flight. Due to the periodicity of the SHR, it may be vulnerable to attack. This document describes interoperable secure ranging devices (SRDEVs) featuring enhanced immunity to attack. The main enhancement is the inclusion of a Scrambled Timestamp Sequence (STS) in the basic HRP PPDU format. Secure Ranging PPDU Formats An SRDEV shall support the basic HRP frame format outlined in [1] §16.2. In addition, SRDEVs shall support the transmission and reception of frames, optimized for Secure Ranging, consisting of: Delimiter) “Synchronization Header” with SFD (Start-of-Frame Timestamp for every frame (according to a Key and a “Scrambled Sequence”, changing Seed, to be defined on higher layer) Fixed DATA (PHR+PSDU) part Three Secure Ranging PPDU formats shall be supported, the difference between the formats being the location of the STS field and the existence of a PHR and PHY Payload field: Figure 1: Secure Ranging Frame Format A (mandatory, avoiding STS timing dependency on payload length) Figure 2: Secure Ranging Frame Format B (optional, backward compatible in case of 62.4 MHz Mean PRF and legacy PHR data rate) Figure 3: Secure Ranging Frame Format C (Optional) Secure ranging frame format C is intended for certain use cases where the participants in the secure ranging exchange are known to each other such that information about source and/or destination are implicit in the knowledge of what STS is used for transmission and reception between the connected devices, respectively. Mean PRF A nominal mean PRF of at least 62.4 MHz shall be used for all packets during a ranging session. Nominal mean PRFs lower than 62.4 MHz are not required for SRDEVs.
Introduction Present HRP ranging-capable devices (RDEVs) use the content of the SHR to estimate time of flight. Due to the periodicity of the SHR, it may be vulnerable to attack. This document describes interoperable secure ranging devices (SRDEVs) featuring enhanced immunity to attack. The main enhancement is the inclusion of a Scrambled Timestamp Sequence (STS) in the basic HRP PPDU format. Secure Ranging PPDU Formats An SRDEV shall support the basic HRP frame format outlined in [1] §16.2. In addition, SRDEVs shall support the transmission and reception of frames, optimized for Secure Ranging, consisting of: “Synchronization Header” with SFD (Start-of-Frame Delimiter) “Scrambled Timestamp Sequence”, changing for every frame (according to a Key and a Seed, to be defined on higher layer) Fixed DATA (PHR+PSDU) part Three Secure Ranging PPDU formats shall be supported, the difference between the formats being the location of the STS field and the existence of a PHR and PHY Payload field: Figure 1: Secure Ranging Frame Format A (mandatory, avoiding STS timing dependency on payload length) Figure 2: Secure Ranging Frame Format B (optional, backward compatible in case of 62.4 MHz Mean PRF and legacy PHR data rate) Figure 3: Secure Ranging Frame Format C (Optional) Secure ranging frame format C is intended for certain use cases where the participants in the secure ranging exchange are known to each other such that information about source and/or destination are implicit in the knowledge of what STS is used for transmission and reception between the connected devices, respectively. Mean PRF A nominal mean PRF of at least 62.4 MHz shall be used for all packets during a ranging session. Nominal mean PRFs lower than 62.4 MHz are not required for SRDEVs.