SCMS CV Pilots Documentation : Glossary

The Advanced Encryption Standard (AES), also known as Rijndael (its original name), is a specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology (NIST) in 2001

Aftermarket Safety Device

Basic Safety Message as defined in the SAE J2735 standard

In computer networking, a service set is a set consisting of all the devices associated with a consumer or enterprise IEEE 802.11 wireless local area network (WLAN). The service set can be local, independent, extended or mesh.

Service sets have an associated identifier, the Service Set Identifier (SSID), which consists of 32 octets that frequently contains a human readable identifier of the network.

The basic service set (BSS) provides the basic building-block of an 802.11 wireless LAN. In infrastructure mode, a single access point (AP) together with all associated stations (STAs) is called a BSS; not to be confused with the coverage of an access point, known as the basic service area (BSA). The access point acts as a master to control the stations within that BSS; the simplest BSS consists of one access point and one station. In OCB mode there is no access point and therefore all stations within reach is called a BSS.

In cryptography, a certificate authority or certification authority (CA) is an entity that issues digital certificates. A digital certificate certifies the ownership of a public key by the named subject of the certificate.

Crash Avoidance Metrics Partners LLC

CCM mode (Counter with CBC-MAC) is a mode of operation for cryptographic block ciphers. It is an authenticated encryption algorithm designed to provide both authentication and confidentiality. CCM mode is only defined for block ciphers with a block length of 128 bits.

Communication Network Vehicle Road Global Extension (CONVERGE): Pioneering approaches to traffic management and vehicle safety issues are increasingly growing together. Still a holistic system architecture for flexible interaction between different service providers and communications network operators is missing in a decentralized, scalable structure. The aim of the project CONVERGE is to close this gap.

A Central Processing Unit (CPU) is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logical, control and input/output (I/O) operations specified by the instructions. The term has been used in the computer industry at least since the early 1960s.Traditionally, the term "CPU" refers to a processor, more specifically to its processing unit and control unit (CU), distinguishing these core elements of a computer from external components such as main memory and I/O circuitry.

Certificate Revocation Authorizing Certificate Authority

In the operation of some cryptosystems, usually public key infrastructures (PKIs), a Certificate Revocation List (CRL) is a list of certificates (or more specifically, a list of serial numbers for certificates) that have been revoked, and therefore, entities presenting those (revoked) certificates should no longer be trusted.

Certificate Revocation List Generator

Device Configuration Manager.Attests to the ECA that an EE device is eligible to receive enrollment certificates, and provides all relevant configuration settings and certificates during bootstrapping.

Domain Name Servers (DNS) are the Internet's equivalent of a phone book. They maintain a directory of domain names and translate them to Internet Protocol (IP) addresses. This is necessary because, although domain names are easy for people to remember, computers or machines, access websites based on IP addresses.

Dedicated Short-Range Communications (DSRC) are one-way or two-way short-range to medium-range wireless communication channels specifically designed for automotive use and a corresponding set of protocols and standards.

In cryptography, a mode of operation is an algorithm that uses a block cipher to encrypt messages of arbitrary length in a way that provides confidentiality or authenticity. A block cipher by itself is only suitable for the secure cryptographic transformation (encryption or decryption) of one fixed-length group of bits called a block. A mode of operation describes how to repeatedly apply a cipher's single-block operation to securely transform amounts of data larger than a block. The simplest of the encryption modes is the Electronic Codebook (ECB) mode. The message is divided into blocks, and each block is encrypted separately.

The Elliptic Curve Digital Signature Algorithm (ECDSA) offers a variant of the Digital Signature Algorithm (DSA) which uses elliptic curve cryptography.

Elliptic Curve Integrated Encryption Scheme, or ECIES, is a hybrid encryption system proposed by Victor Shoup in 2001. ECIES has been standardized in ANSI X9.63, IEEE 1363a, ISO/IEC 18033-2, and SECG SEC-1. ECIES combines a Key Encapsulation Mechanism (KEM) with a Data Encapsulation Mechanism (DEM). The system independently derives a bulk encryption key and a MAC key from a common secret. Data is first encrypted under a symmetric cipher, and then the cipher text is MAC'd under an authentication scheme. Finally, the common secret is encrypted under the public part of a public/private key pair. The output of the encryption function is the tuple {K,C,T}, where K is the encrypted common secret, C is the ciphertext, and T is the authentication tag. There is some hand waiving around the "common secret" since its actually the result of applying a Key Agreement function, and it uses the static public key and an ephemeral key pair.

In cryptography, implicit certificates are a variant of public key certificate, such that a public key can be reconstructed from any implicit certificate, and is said then to be implicitly verified, in the sense that the only party who can know the associated private key is the party identified in the implicit certificate. This does not rule out the possibility that nobody knows the private key, but this possibility is not considered a major problem.

By comparison, traditional public-key certificates include a copy of the public key and the digital signature of the certificate authority. Upon verification of the digital signature, the public key is explicitly verified, in the sense that the party identified in the certificate knows the associated private key and is the only party who can know the private key. Unlike an implicit certificate, there is no possibility that nobody knows the private key. For the purposes of this document, such certificates will be called explicit certificates.

Elliptic Curve Qu-Vanstone (ECQV) are one kind of implicit certificates.

The European Geostationary Navigation Overlay Service (EGNOS) is a satellite based augmentation system (SBAS) developed by the European Space Agency, the European Commission and EUROCONTROL. It supplements the GPS, GLONASS and Galileo systems by reporting on the reliability and accuracy of the positioning data.

According to specifications, horizontal position accuracy should be better than seven metres. In practice, the horizontal position accuracy is at the metre level. The EGNOS system consists of four geostationary satellites and a network of ground stations.

Electors represent the center of trust of the SCMS. Electors sign ballots that either endorse or revoke an RCA or another elector. The SCMS Manager distributes those ballots to all SCMS components, including devices, to establish trust relationships in RCAs and electors. An elector has a self-signed certificate, and all entities of the system will implicitly trust the initial set of electors. Therefore, all entities have to protect electors against unauthorized alteration, once they installed the initial set.

The Federal Highway Administration (FHWA) is a division of the United States Department of Transportation that specializes in highway transportation.

In telecommunications and signal processing, frequency modulation (FM) is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave. This contrasts with amplitude modulation, in which the amplitude of the carrier wave varies, while the frequency remains constant.

Federal Motor Vehicle Safety Standards (FMVSS) are U.S. federal regulations specifying design, construction, performance, and durability requirements for motor vehicles and regulated automobile safety-related components, systems, and design features.

Global Detection

A satellite navigation system with global coverage may be termed a global navigation satellite system (GNSS). A satellite navigation or satnav system is a system that uses satellites to provide autonomous geo-spatial positioning. It allows small electronic receivers to determine their location (longitude, latitude, and altitude/elevation) to high precision (within a few metres) using time signals transmitted along a line of sight by radio from satellites. The system can be used for navigation or for tracking the position of something fitted with a receiver (satellite tracking). The signals also allow the electronic receiver to calculate the current local time to high precision, which allows time synchronisation. Satnav systems operate independently of any telephonic or internet reception, though these technologies can enhance the usefulness of the positioning information generated.

Hybrid-Digital

A hardware security module (HSM) is a physical computing device that safeguards and manages digital keys for strong authentication and provides cryptoprocessing. These modules traditionally come in the form of a plug-in card or an external device that attaches directly to a computer or network server.

The Hypertext Transfer Protocol (HTTP) is an application protocol for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web.

Hypertext is structured text that uses logical links (hyperlinks) between nodes containing text. HTTP is the protocol to exchange or transfer hypertext.

HTTPS (also called HTTP over TLS, HTTP over SSL, and HTTP Secure) is a protocol for secure communication over a computer network which is widely used on the Internet. HTTPS consists of communication over Hypertext Transfer Protocol (HTTP) within a connection encrypted by Transport Layer Security (TLS) or its predecessor, Secure Sockets Layer (SSL). The main motivation for HTTPS is authentication of the visited website and protection of the privacy and integrity of the exchanged data.

Intermediate certificate authority (ICA): there are two types of certificate authorities (CAs), root CAs and intermediate CAs. The ICA serves as a secondary Certificate Authority to shield the RCA from traffic and attacks. The RCA issues the Intermediate CA certificate.

The Internet Corporation for Assigned Names and Numbers (ICANN /ˈaɪkæn/ EYE-kan) is a nonprofit organization that is responsible for coordinating the maintenance and procedures of several databases related to the namespaces of the Internet - thereby ensuring the network's stable and secure operation. ICANN performs the actual technical maintenance work of the central Internet address pools and DNS Root registries pursuant to the Internet Assigned Numbers Authority (IANA) function contract.

The Internet Protocol (IP) is the principal communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet.

Internet Protocol version 4 (IPv4) is the fourth version of the Internet Protocol (IP). It is one of the core protocols of standards-based internetworking methods in the Internet, and was the first version deployed for production in the ARPANET in 1983. It still routes most Internet traffic today, despite the ongoing deployment of a successor protocol, IPv6. IPv4 is described in IETF publication RFC 791 (September 1981), replacing an earlier definition (RFC 760, January 1980).

IPv4 is a connectionless protocol for use on packet-switched networks. It operates on a best effort delivery model, in that it does not guarantee delivery, nor does it assure proper sequencing or avoidance of duplicate delivery. These aspects, including data integrity, are addressed by an upper layer transport protocol, such as the Transmission Control Protocol (TCP).

Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communications protocol that provides an identification and location system for computers on networks and routes traffic across the Internet. IPv6 was developed by the Internet Engineering Task Force (IETF) to deal with the long-anticipated problem of IPv4 address exhaustion. IPv6 is intended to replace IPv4.

The ITS Joint Program Office (ITS JPO), within the Office of the Assistant Secretary for Research and Technology (OST-R), is charged with executing Subtitle C- Intelligent Transportation System Research of Public Law 109-59 Safe Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users, enacted August 10, 2005.

Linkage Authority. Generates pre-linkage values, which are used to form linkage values that go in the certificates and support efficient revocation. There are two LAs in the SCMS, referred to as LA1 and LA2. The splitting prevents the operator of an LA from linking certificates belonging to a particular device.

Linkage Chain Identifier

Linkage Seed

Linkage Value

Misbehavior Authority. Processes misbehavior reports to identify potential misbehavior or malfunctioning by devices, and revokes and adds them to the CRL, if necessary. It also initiates the process of linking a certificate identifier to the corresponding enrollment certificates and adding them to the RA's internal blacklist. The MA contains two subcomponents: Global Misbehavior Detection, which determines which devices are misbehaving; and CRL Generator, which generates, digitally signs and releases the CRL to the public.

The Media Access Control (MAC) Layer is one of two sublayers that make up the Data Link Layer of the Open System Interconnection (OSI) model. The MAC layer is responsible for moving data packets to and from one Network Interface Card to another across a shared channel.

In cryptography, a Message Authentication Code (MAC) is a short piece of information used to authenticate a message and to provide integrity and authenticity assurances on the message.

The National Highway Traffic Safety Administration (NHTSA) is an agency of the Executive Branch of the U.S. government, part of the Department of Transportation. It describes its mission as "Save lives, prevent injuries, reduce vehicle-related crashes."

As part of its activities, NHTSA is charged with writing and enforcing Federal Motor Vehicle Safety Standards as well as regulations for motor vehicle theft resistance and fuel economy, the latter under the rubric of the Corporate Average Fuel Economy (CAFE) system. NHTSA also licenses vehicle manufacturers and importers, allows or blocks the import of vehicles and safety-regulated vehicle parts, administers the vehicle identification number (VIN) system, develops the anthropomorphic dummies used in safety testing, as well as the test protocols themselves, and provides vehicle insurance cost information. The agency has asserted preemptive regulatory authority over greenhouse gas emissions, but this has been disputed by such state regulatory agencies as the California Air Resources Board.

The National Institute of Standards and Technology (NIST) is a measurement standards laboratory, and a non-regulatory agency of the United States Department of Commerce. Its mission is to promote innovation and industrial competitiveness.

NIST's activities are organized into laboratory programs that include Nanoscale Science and Technology, Engineering, Information Technology, Neutron Research, Material Measurement, and Physical Measurement.

Network Time Protocol (NTP) is a networking protocol for clock synchronization between computer systems over packet-switched, variable-latency data networks. In operation since before 1985, NTP is one of the oldest Internet protocols in current use.

NTP is intended to synchronize all participating computers to within a few milliseconds of Coordinated Universal Time (UTC). It uses a modified version of Marzullo's algorithm to select accurate time servers and is designed to mitigate the effects of variable network latency. NTP can usually maintain time to within tens of milliseconds over the public Internet, and can achieve better than one millisecond accuracy in local area networks under ideal conditions. Asymmetric routes and network congestion can cause errors of 100 ms or more.

On-board Equipment

Pseudonym Certificate Authority. Issues short-term pseudonym, identification, and application certificates to devices. Individual PCAs may be, e.g., limited to a particular geographic region, a particular manufacturer, or a type of device.

In telecommunications, the term protocol data unit (PDU) has the following meanings:

• Information that is delivered as a unit among peer entities of a network and that may contain control information, such as address information, or user data.
• In a layered system, a unit of data which is specified in a protocol of a given layer and which consists of protocol-control information and possibly user data of that layer.

A Public Key Infrastructure (PKI) is a set of hardware, software, people, policies, and procedures needed to create, manage, distribute, use, store, and revoke digital certificates and manage public-key encryption.

Pre-Linkage Value

The Provider Service Identifier (PSID) is a four-byte numeric string used by the IEEE 1609 set of standards to identify a particular application service provider that announces that it is providing a service to potential users of an application or service.

In a PKI there are two types of certificate authorities (CAs), root CAs (RCA) and intermediate CAs. An RCA is the root at the top of a certificate chain in the SCMS and hence a trust anchor in a traditional PKI sense. It issues certificates for ICAs as well as SCMS components like PG and MA. An RCA has a self-signed certificate, and a ballot with a quorum vote of the electors establishes trust in an RCA. RCA certificates must be stored in secure storage that is usually referred to as a Trust Store. An entity verifies any certificate by verifying all certificates along the chain from the certificate at hand to the trusted RCA. This concept is called chain-validation of certificates and is the fundamental concept of any PKI. If the RCA and its private key are not secure, then the system is potentially compromised. Due to its importance, an RCA is typically off-line when not in active use.

Radio frequency (RF) is any of the electromagnetic wave frequencies that lie in the range extending from around 3 kHz to 300 GHz, which include those frequencies used for communications or radar signals.

RSA is one of the first practical public-key cryptosystems and is widely used for secure data transmission. In such a cryptosystem, the encryption key is public and differs from the decryption key, which is kept secret. In RSA, this asymmetry is based on the practical difficulty of factoring the product of two large prime numbers. RSA is made of the initial letters of the surnames of Ron Rivest, Adi Shamir, and Leonard Adleman, who first publicly described the algorithm in 1977.

Road-side Equipment. Synonym for RSU. Equivalent to RSU definition in DSRC Roadside Unit (RSU) Specifications Document v4.1

Augmentation of a global navigation satellite system (GNSS) is a method of improving the navigation system's attributes, such as accuracy, reliability, and availability, through the integration of external information into the calculation process. There are many such systems in place and they are generally named or described based on how the GNSS sensor receives the external information. Some systems transmit additional information about sources of error (such as clock drift, ephemeris, or ionospheric delay), others provide direct measurements of how much the signal was off in the past, while a third group provide additional vehicle information to be integrated in the calculation process.

A satellite-based augmentation system (SBAS) is a system that supports wide-area or regional augmentation through the use of additional satellite-broadcast messages. Such systems are commonly composed of multiple ground stations, located at accurately-surveyed points. The ground stations take measurements of one or more of the GNSS satellites, the satellite signals, or other environmental factors which may impact the signal received by the users. Using these measurements, information messages are created and sent to one or more satellites for broadcast to the end users.

The Security Credential Management System (SCMS) is the term used to identify the PKI used in the U.S. V2X system.

Simple Network Management Protocol (SNMP) is an Internet-standard protocol for collecting and organizing information about managed devices on IP networks and for modifying that information to change device behavior. Devices that typically support SNMP include routers, switches, servers, workstations, printers, modem racks and more.

SNMP is widely used in network management for network monitoring. SNMP exposes management data in the form of variables on the managed systems organized in a management information base which describe the system status and configuration. These variables can then be remotely queried (and, in some circumstances, manipulated) by managing applications.

Simple Object Access Protocol (SOAP) is a messaging protocol that allows programs that run on disparate operating systems (such as Windows and Linux) to communicate using Hypertext Transfer Protocol (HTTP) and its Extensible Markup Language (XML).

The Transmission Control Protocol (TCP) is a core protocol of the Internet Protocol Suite. It originated in the initial network implementation in which it complemented the Internet Protocol (IP). Therefore, the entire suite is commonly referred to as TCP/IP.

A true random number generator (TRNG) is a device that generates random numbers from a physical process, rather than a computer program. Such devices are often based on microscopic phenomena that generate low-level, statistically random "noise" signals, such as thermal noise, the photoelectric effect, involving a beam splitter, and other quantum phenomena. These processes are, in theory, completely unpredictable, and the theory's assertions of unpredictability are subject to experimental test.

The main application for electronic hardware random number generators is in cryptography, where they are used to generate random cryptographic keys to transmit data securely.

The United States Department of Defense (USDOD or DoD) is an executive branch department of the federal government of the United States charged with coordinating and supervising all agencies and functions of the government concerned directly with national security and the United States Armed Forces. It is headquartered at the Pentagon in Arlington, Virginia, just outside of Washington, D.C.

The United States Department of Transportation (USDOT or DOT) is a federal Cabinet department of the U.S. government concerned with transportation. It was established by an act of Congress on October 15, 1966, and began operation on April 1, 1967.

Universal Time (UT) is a time standard based on Earth's rotation. It is a modern continuation of Greenwich Mean Time (GMT), i.e., the mean solar time on the Prime Meridian at Greenwich, London, UK. In fact, the expression "Universal Time" is ambiguous (when accuracy of better than a few seconds is required), as there are several versions of it, the most commonly used being Coordinated Universal Time (UTC) and UT1. All of these versions of UT, except for UTC, are based on Earth's rotation relative to distant celestial objects (stars and quasars), but with a scaling factor and other adjustments to make them closer to solar time. UTC is based on International Atomic Time, with leap seconds added to keep it within 0.9 second of UT1.

UT1 is the principal form of Universal Time. While conceptually it is mean solar time at 0° longitude, precise measurements of the Sun are difficult. Hence, it is computed from observations of distant quasars using long baseline interferometry, laser ranging of the Moon and artificial satellites, as well as the determination of GPS satellite orbits. UT1 is the same everywhere on Earth, and is proportional to the rotation angle of the Earth with respect to distant quasars, specifically, the International Celestial Reference Frame (ICRF), neglecting some small adjustments. The observations allow the determination of a measure of the Earth's angle with respect to the ICRF, called the Earth Rotation Angle (ERA, which serves as a modern replacement for Greenwich Mean Sidereal Time). UT1 is required to follow the relationship

ERA = 2π(0.7790572732640 + 1.00273781191135448T_u) radians, where T_u = (Julian UT1 date - 2451545.0)

Coordinated Universal Time (UTC), is the primary time standard by which the world regulates clocks and time. It is within about 1 second of mean solar time at 0° longitude; it does not observe daylight saving time. It is one of several closely related successors to Greenwich Mean Time (GMT). For most purposes, UTC is considered interchangeable with GMT, but GMT is no longer precisely defined by the scientific community.

UTC was officially formalized in 1960 by the International Radio Consultative Committee in Recommendation 374, having been initiated by several national time laboratories. The system was adjusted several times until leap seconds were adopted in 1972 to simplify future adjustments. A number of proposals have been made to replace UTC with a new system that would eliminate leap seconds, but no consensus has yet been reached.

The current version of UTC is defined by International Telecommunications Union Recommendation (ITU-R TF.460-6), Standard-frequency and time-signal emissions and is based on International Atomic Time (TAI) with leap seconds added at irregular intervals to compensate for the slowing of Earth's rotation. Leap seconds are inserted as necessary to keep UTC within 0.9 seconds of universal time, UT1.

Vehicle Infrastructure Integration Consortium

A Virtual Private Network (VPN) extends a private network across a public network, such as the Internet. It enables users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network, and, thus, are benefiting from the functionality, security and management policies of the private network.A VPN establishes a virtual point-to-point connection using dedicated connections, virtual tunneling protocols, or traffic encryption.

Vehicle Safety Communications 3 (CAMP Consortium)

The World Geodetic System (WGS) is a standard for use in cartography, geodesy, and navigation including by GPS. It comprises a standard coordinate system for the Earth, a standard spheroidal reference surface (the datum or reference ellipsoid) for raw altitude data, and a gravitational equipotential surface (the geoid) that defines the nominal sea level.

The WAVE Management Entity (WME) represents another entity that is unique to WAVE standards and performs much of the operations unique to WAVE standards. For instance, when data frames are scheduled, the transmission channel must be defined along with QoS priorities. Those priorities must allow an emergency safety message to be transmitted at anytime with very limited latency. Management of frame queuing, priority channels and handling of safety messages are quite unique to WAVE standards. The WME handles those particular processing in coordination with other design entities.

WAVE Short Message

WAVE Service Advertisement

WAVE communication services provide data communications over two protocol stacks, namely; IPv6 and WAVE Short Message Protocol (WSMP). WSMP is unique to the WAVE standards and is designed for use by specialized applications like safety applications. Applications using WSMP may initiate a WBSS to configure the Service Channel (SCH) for their use. But availability of SCH is optional since WSMP can be exchanged on the Control Channel (CCH) even in the absence of WBSS (i.e., in a V2V scenario).