Information Elements. In the mean time, Public Key Cryptography (PKC) - a fundamental building block in most KMPs - has become viable also on constrained devices. Indeed, we are now at a point in time where Elliptic Curve Cryptography (ECC) is not only affordable on today’s ever more powerful and (memory) capable constrained devices [7], [16], but it is even cheap and natively introduced in the latest generation of IIoT devices [14]. Such technological evolution is bringing us to a point where the primary concern is not anymore the computationally efficient support of ECC, but rather stems in how to use such primitives for building airtime-efficient authentication and key management protocols. Indeed, most of the proposed PKC- based handshakes [15] suffer from a significant shortcoming in terms of number and size of the messages exchanged [18]. In particular, transmission of long messages containing conventional X.509 certificates [12] yields a sizeable airtime consumption, whose major consequences are i) a significant latency in the authentication protocol when run over a typical low-rate communication channel, and ii) a significant power consumption, being airtime a major power drain component. Contribution. Based on these premises, the contribution of this letter is threefold. First, our proposed approach is among the first to concretely integrate and experimentally evaluate “implicit” Elliptic Curve Qu-Vanstone (ECQV) certificates [1] within an authentication and key agreement protocol devised for IIoT devices and scenarios. While in our former work [18] performance were affected by a software implementation of the ECC primitives, this work shows that the viability of such technique is greatly improved by the native (e.g., hardware) and efficient support of ECC over modern IIoT de- vices. Second, our novel proposed KMP relies on an ordinary and widely established “fixed” Elliptic Curve Xxxxxx-Xxxxxxx (ECDH) exchange [6], which provides authentication without any explicit signature, as well as ephemeral key derivation (and very fast re-keying, when necessary). This is obtained by exchanging per-session nonces and by securing the ex- change using a minimized number of messages (two per each direction, i.e., four in total). Finally, experimental performance results over both single-hop and multi-hop networks show significant improvements in terms of maximal airtime savings (up to 86,7%) with respect to a traditional approach relying on an ECDH exchange with public coefficients...
Information Elements. A.2.1 Protocol discriminator No changes.
Information Elements. This subclause defines the information elements (IEs) that can appear in beacons and certain command frames. The general format of all IEs is illustrated in Figure 42. octets: 1 1 N Element ID Length (=N) IE-specific fields Figure 42 — General IE format The Element ID field is set to the value as listed in Table 61 that identifies the information element. The Length field is set to the length, in octets, of the IE-specific fields that follow. The IE-specific fields contain information specific to the IE. Table 61 contains a list of IEs defined in this standard. Table 61 — Information elements Element ID Information element Description 0 Traffic Indication Map (XXX) IE Indicates that a device has data buffered for transmission via PCA 1 Beacon Period Occupancy IE (BPOIE) Provides information on neighbors’ BP occupancy in the previous superframe 2 PCA Availability IE Indicates the MASs that a device is available to receive PCA frames and transmit the required response 8 DRP Availability IE Indicates a device’s availability for new DRP reservations 9 Distributed Reservation Protocol (DRP) IE Indicates a reservation with another device 10 Hibernation Mode IE Indicates the device will go to hibernation mode for one or more superframes but intends to wake at a specified time in the future 11 BP Switch IE Indicates the device will change its BPST at a specified future time 12 MAC Capabilities IE Indicates which MAC capabilities a device supports 13 PHY Capabilities IE Indicates which PHY capabilities a device supports 14 Probe IE Indicates a device is requesting one or more IEs from another device or/and responding with requested IEs 15 Application-specific Probe IE Indicates a device is requesting an Application-specific IE from another device 16 Link Feedback IE Provides data rate and power control feedback 17 Hibernation Anchor IE Provides information on devices in hibernation mode 18 Channel Change IE Indicates a device will change to another channel 19 Identification IE Provides identifying information about the device, including a name string 20 Master Key Identifier (MKID) IE Identifies some or all of the master keys held by the transmitting device 21 Relinquish Request IE Indicates that a neighbor requests that a device release one or more MASs from its reservations.
Information Elements. X.36 Section 10.5 General message format and information element coding Section 10.5.5 Call state: See section 2.5.5.7 of this document. The global interface state values apply to the Call state information element.
Information Elements
