ES2372841A1 - System for securely communicating in a spontaneous self-managed ad-hoc vehicular network - Google Patents

Abstract

System for securely communicating in a spontaneous self-managed ad-hoc vehicular network, without infrastructures on either the road or in vehicles, using only mobile devices with a global satellite navigation system receiver and with wireless communication and computation capability such as mobile telephones, PDAs and portable computers. The operating mode envisaged in the invention is completely distributed and decentralized and takes into account the protection of the privacy of the drivers and defence against possible attacks.

Description

Secure communications system in a spontaneous and self-managed vehicular ad-hoc network.

Technical sector

Telecommunications Mobile communications and Wireless between vehicles.

Introduction

The present invention relates to the security of communications in ad-hoc vehicular networks or VANETs (Vehicular Ad-hoc NETworks). This security currently represents a challenge to be solved since it is anticipated that these networks will be an important revolution for the safety and comfort of road transport in the not too distant future.

In the VANETs the messages exchanged between the vehicles will influence the behavior of their drivers as these, for example, will reduce speed and / or choose routes alternatives based on the information received. Any malicious user could try to exploit this situation, carrying out any of the following attacks:

- Injection of false, modified or repeated, spreading erroneous data that may affect the rest of vehicles, either for the benefit of the attacker for example when getting free a way, or simply by bad intention for example to produce a jam.

- Identity forgery (posing as for example by an emergency vehicle) or manipulation of the information sent (altering data such as position, address, speed, etc.) for example to try to escape from responsibilities having caused an accident.

- Tracking drivers and / or vehicles, threatening your privacy and anonymity.

- Denial of service, causing loss of network connectivity.

Therefore, the security of communications is an essential factor in preventing such threats and enable the deployment of VANETs.

Although the general approach of the invention can be used in different applications of the VANETs, the analyzes carried out and the concrete realization described at the end of this document are focused on reducing traffic jams in the highway.

State of the art

There are several initiatives both from the industry as from the academic environment intended to make possible the future exploitation of the VANETs. However, all Existing proposals have in common the hypothetical existence previous infrastructure on the road or RSU (Road-Side Unit) and / or the use of mobile telephony, and / or Internet and / or devices on board vehicles or OBUs (On-Board Units).

For example the draft standard of communications for VANETs, IEEE 802.11p WAVE (Wireless Access for Vehicular Environments, http://grouper.ieee.org/groups/802/11/Reports) that is being developed by the consortium Car-2-car (http://www.car-to-car.org) presupposes that the VANETs will combine several wireless technologies as Cellular, Satellite, WiMAX (Worldwide Interoperability for Microwave ACCess, http://www.ieee802.org/16) and DSR communications (Dedicated Short Range).

Similarly, the CALM architecture (Communications, Air interface, Long and Medium range,
http://www.isotc204wg16.org/concept), also in the process of standardization by the ISO organization (International Organization for Standardization), aims to support communications in mobile environments and in particular in ITSs (Intelligent Transportation Systems), through combined use of various wireless technologies such as WAVE, UMTS (Universal Mobile Telecommunications System, http://www.3GPP.org), WiMAX or RFID (Radio Frequency ID identification), and the application of various international standards, interfaces and media, such as IEEE 802.11, 802.11p, 802.15, 802.16e, 802.20, 2G / 3G / 4G mobile telephony, and national ITSs.

In both standards, the safety of communications is based on the combination of technologies mentioned, generally assuming the use of infrastructure of public key with certification based on centralized authorities, which implies the need for prior implementation of RSUs in roads and OBUs in vehicles.

On the other hand, the solutions proposed in various research projects are based on the availability of OBUs on vehicles, and / or RSUs on the road, which it would imply a large initial outlay by the State and / or by the users. In fact, most of the research efforts in this field it is being done from car companies, so that in the proposals it is normally assumed that in the OBUs integrated into vehicles there is a black box, an identity certified, sensors to detect obstacles, an interface human-machine, and a device of proof fakes to do the calculations, plus a receiver of a Global Satellite Navigation System and a device Wifi.

Among the related scientific publications With the security in the VANETs, the following stand out:

- Philippe Golle , Dan Greene and Jessica Staddon , "Detecting and correcting malicious data in VANETs", 1st ACM international workshop on Vehicular ad hoc networks pp. 29-37. 2004 Proposes the use of sensors to detect incorrect information.

- Maxim Raya and Jean-Pierre Hubaux , "The security of vehicular ad hoc networks", 3rd ACM workshop on Security of ad hoc and sensor networks pp. 11-21. 2005 It assumes the existence of certification authorities to issue certificates to vehicles, proposing that they be government authorities or vehicle manufacturers.

- Florian Dötzer , "Privacy Issues in Vehicular Ad Hoc Networks", Lecture Notes in Computer Science 3856 pp. 197-209. 2006 It involves the participation of vehicle manufacturers since during the production of each vehicle a secure connection must be established with a certifying authority that validates the OBU.

Among the patents, the following stand out documents related to the VANETs.

US2008002635 and US2008002574 propose a method to manage communications traffic, measuring levels local and defining a microutility of the data to be transmitted to select the transmission medium.

US20080279141 describes an allocation method from channels to multihop communications between one node and another, to Sending information through routing.

WO2008092475 proposes the dissemination of information through unicast.

WO2008104673 raises the estimate of the node density by dividing into geographic cells in that the node closest to the center is responsible for adding and Relay the information.

WO2008119948 is based on the use of telephony mobile to define an information routing algorithm between two nodes

WO2009024945 describes a method to synchronize radio-communicated devices through periodic beacons that Include clock signals.

WO2009053657 proposes that at intersections of roads the broadcast of information is done through a node chosen within a group based on the estimated time for reach the intersection.

WO2010020260 presents a method for sending information from a source node to a destination node using routing through intermediate nodes.

WO2010040372 presupposes the use of a infrastructure on the road to control the load of wireless channel communications, defining priorities over the messages to set your shipping characteristics.

However, none were found precedent that describes a safe and cheaper solution than proposals so far. In this sense our invention avoids the need to install any type of infrastructure even in the vehicle or on the road, which means saving on investment economic and waiting time for the development of multiple applications of vehicle networks, allowing start-up VANETs without any investment from governments, companies automobile or telephone companies.

A secure communications system is presented here in a spontaneous and self-managed vehicular ad-hoc network, without infrastructures either on the road or in vehicles, using only mobile devices with a receiver of a global satellite navigation system, and wireless and wireless communication capability. computing, such as mobile phones, PDAs and laptops.

The mode of operation provided for in the invention is fully distributed and decentralized, and has in account the protection of the privacy of the drivers and the defense against possible attacks. Both issues involve the possibility of progressive deployment with effective functionality and security from the first moment.

The key factors of the proposed design are: scalability and economy, authentication of nodes and information, privacy, promotion of cooperation, and low delay and stability of communications

A system that can be integrated into specific mobile devices, or be implemented in existing devices on the market such as mobile phones equipped with adequate software.

Brief Description of the Invention

The first fundamental element of this invention is a self-managed authentication method, which does not requires the intervention of certification authorities since they are the nodes themselves which certify the validity of the keys public of the nodes they trust, issuing the corresponding certificates, which are stored in warehouses local and updated using an algorithm described here. Further, the node authentication proposal includes a protocol cryptographic, which allows each node to convince another node of the possession of a certain secret without the information transmitted let you discover anything about this secret, preventing possible impersonation attacks.

A second fundamental element of this invention is a symmetric encryption algorithm used in Different phases All those are contemplated for your design Known parameters that guarantee the safety of non-filtered linear in encrypted in flow.

Finally, the present invention also contemplates as a third fundamental element an aggregation scheme of data that includes the generation of aggregated packages from groups created ad-hoc for it, and the verification of digital signatures in a probabilistic way.

In the present invention it is assumed that each node The network is characterized by the following parameters:

ID, (KU_ {ID}, KR_ {ID}), \ {ID_ {i}, KU_ {IDi}, Cert (KU_ {IDi}) \} _ {IDi \ \ in \ Warehouse}

including:

- a unique ID (denoted ID), obtained by applying a unidirectional function on a value only. For example, if the device used is a mobile phone, you can use the number, while in other cases you can use a Email address. The unidirectional function could be a hash function, such as MD5.

- a fixed public / private key pair (denoted (KU, KR) and key identity calls to use in a asymmetric cryptosystem, such as RSA.

- a store containing several IDs, and corresponding public keys KUs and certificates, that the node keeps updated at all times, in the way:

100

Detailed description of the invention

Secure communications system in a spontaneous and self-managed vehicular ad-hoc network comprising the following modules (see Figure 1):

C1. Generation of identity and signature keys digital

It is part of the first fundamental element of the invention. This generation is necessary since the authentication of nodes proposed in this invention is based on self-managed public key cryptography without requiring certification authorities at any time. Instead, each node is responsible for generating its own public / private key pairs, which are essential for authentication processes, and for digital signature of the messages it sends once authenticated. Each node has a fixed pair of public / private keys (identity keys) whose validity is certified in a self-managed way through their own public key stores
nodes

C2 Client / server architecture with the possibility of connection to multiple users at once

It is necessary for the first fundamental element of the invention. It is that each node (client) performs requests to another node (server), which responds to it (see Figure 2). This idea is very useful in distributed multi-user systems such as the vehicular network object of this invention because thus the Process capacity is shared between clients and servers. In particular in this invention this component is necessary for the interconnection of the nodes since it allows to send and receive messages from many clients and to many servers at once as each User is both client and server.

C3 Multicast sending and wireless reception of beacons with variable pseudonyms

It is part of the first fundamental element of the invention. Sending / receiving messages containing beacons Variable pseudonyms of the sending nodes is necessary for the discovery process of active nodes, and avoid possible follow-ups (see Figure 2).

C4 Mutual authentication of nodes, with exchange of fixed public keys, temporary secret keys, and warehouses of public keys

It is the basis of the first fundamental element of the invention. The exchange of messages between pairs of nodes has as an object that each one demonstrates to the other who knows a secret without reveal nothing about him. The proposed scheme is based on a scheme challenge-response interactive, as shown in Figure 3. In the step of sending beacons each node commits in front of their neighbors with what they intend to demonstrate, sending them a witness (D1). If a node A wishes to establish contact with another node B, sends you a random challenge (D2). Then B returns the answer (D3) corresponding to the challenge and the witness. After these steps, both nodes share a key that they use to encrypt and send their public identity key. Then they exchange their temporary secret keys encrypted with the other's public key node. Finally everyone uses their own secret key to encrypt and send encrypted keystore. This module allows to guarantee to each node the authenticity of the other, as well as to exchange the secret keys that are used in module C7, and update the public key stores needed for later verification of the validity of public identity keys used for message signing.

C5 Optimal update of key stores public

It is an important part of the first element fundamental of the invention. Limit the number of keys stored at a value denoted lim, so that said value is in general, less than the number of users that make up the network vehicular, and equal to the minimum number allowed, taking advantage of the property of the six degrees of separation consisting in that any node can connect to any other through a chain with no more than six links (see Figure 4), store only the keys needed to authenticate to any other node with a high probability

C6 Node reputation scheme, which erases from the warehouses to dishonest nodes

It is part of the first fundamental element of the invention. It allows to isolate those nodes for which they have been detected incorrect or corrupt behaviors, through the Deleting your public key from certificate stores.

C7 Encrypted exchange of data on elements static and dynamic road

This module constitutes the second element fundamental of the invention. The encrypted exchange of the information obtained on the road and traffic, which have stored at that time the nodes is necessary to avoid passive behaviors of users who intend to take advantage of the VANET without cooperating for its operation. the use of a Secret key cryptosystem is recommended given the size of the data file Our invention proposes to use a password temporary secret of the issuer.

C8 Data authentication

The third fundamental element of the invention It is part of this module. For the proper functioning of the network is It is essential to verify the integrity and origin of the data received by digital signature, evaluation of characteristics verifiable (freshness, location, relevance, correction, etc.) and match checking with aggregation, because it should check at all times that the retransmitted information is Authentic, current and valid. In this self-managed invention this is only possible by combining integrity verification techniques and origin, evaluation of verifiable characteristics, and verification of matches with other messages received by aggregating data.

Description of the figures

\hbox{tales que en
uno de ellos no se requiere la ejecución de los módulos C7 y
C8.}

Figure 1: Conceptual scheme of the system including its 8 basic modules of Key Generation and Signature (C1), Client / Server Architecture (C2), Send and Receive Beacons (C3), Node Authentication (C4), Warehouse Update ( C5), Reputation Scheme (C6), Encrypted Exchange (C7) and Data Authentication (C8). The execution of these modules is not necessarily sequential, since C5 and C6 do not require interaction between nodes, while C7 and C8 do, so that C5 and C6 can be executed in parallel with C7 and C8. In fact, two ways are proposed in the proposed implementation described

 \ hbox {such that in
one of them is not required to execute the C7 modules and
C8.} 

Figure 2: Scheme representing the architecture client / server with connection to multiple users at once, and also multicast sending and wireless reception of beacons

Figure 3: Mutual authentication scheme based in an interactive demonstration of null knowledge between a couple of nodes A and B. In the step of sending beacons B it is committed against to node A with the object to be demonstrated by sending a witness (D1). Yes A You want to make contact with B, send you a random challenge (D2). Finally B returns the answer (D3) corresponding to the challenge and the witness.

Figure 4: Scheme representing the property of the six degrees of separation in the certification environment of public keys between vehicles.

Figure 5: Scheme showing the proposal of embodiment of the invention using the associated mobile phone in first to the hands-free device of a vehicle, so that before starting the vehicle the user enters his destination and route preference, and when the mobile receives information about abnormal speeds of its neighbors, recalculate the route recommended and suggested to the driver.

Figure 6: Generation exemplification proposal of the public identity key KU_ {ID} from a graph and its adjacency matrix, using the elements of the upper triangular submatrix corresponding to a circuit Hamiltonian in the graph.

Figure 7: Scheme representing all interactions between two nodes A and B. First A sends the hash to B {\ forallID \ in Warehouse_ {A}} (P1), in step (P2) B requests to node A the list of IDs of your warehouse, then A sends B the set {\ forallID \ in Warehouse_ {A}} (P3), B checks if there is a key X \ in {Warehouse_ {A} \ capStore_ {B}} and in that case it is sent to node A, (P4). Then A builds and sends B a graph G_ {A} (X) (P5). Then at least two are done three-step iterations in which first A sends a graph to B GI_ {A} (X) (P6) isomorphic to graph G_ {A} (X), then B sends a random binary challenge (P7) to node A, and according to its value A returns to B the isomorphism between both graphs or a circuit Hamiltonian in GI_ {A} (X) (P8). When finished, A uses X to encrypt your KU_ {A} key and send the result to B Ex (KU_ {A}) (P9), then B uses the key KU_ {A} to encrypt your key K_ {B} and send the result to node A KU_ {A} (K_ {B}) (PIO). Finally, A uses its key K_ {A} to encrypt your store and send encryption to B E_ {KA} (Warehouse_ {A}) (P11).

Figure 8: Encryption based sequence generator in a shift register with feedback polynomial primitive coefficients (c_ {L}, c_ {L-1}, ..., c_ {1}) of lower non-zero values, such that the weight of said Coefficient vector is the smallest value greater than 0.07 * L. It includes a filtering function f of order equal to the prime number p plus close to L / 2, linear term corresponding to p, and number of terms of each order i = 1, 2, ..., p equal to [L / i], The output of said filtering is tenth according to the log output, and the output decimated is introduced in a buffer of size 4.

Figure 9: Formation of reactive group generated ad-hoc from the detection of a jam.

Figure 10: Scheme representing the three zones geographical defined for data authentication called zone of danger (Z1), zone of uncertainty (Z2) and zone of security (Z3).

Figure 11: Graphical representation of the use of speed calculation from the distance s traveled in a t time for a node, allowing the device to recalculate automatically the estimated time t_ {e} for the route initially recommended and compare it to the initially estimated time t_ {h} for that route, so if t_ {e} >> t_ {h}, and there is a alternative route with estimated time t_ {a} << t_ {e}, the device recommends this route to the driver.

Embodiment of the invention

Although the general approach of the invention can be used in different applications of the VANETs, the analyzes carried out and the concrete realization described as embodiment are focused on the objective of the reduction of traffic jams on the road.

In this case, mobile phones are used as mobile devices, so that the node representing the vehicle within the vehicular network at all times is the phone Passenger mobile associated first to the hands device vehicle free. This last assumption avoids the possibility of that in a vehicle there are several devices of its passengers that may be listed on the VANET, as this would lead to erroneous conclusions about vehicle density on the road. In addition, at the time of synchronization of the mobile phone as first device associated with the hands-free device, the telephone mobile automatically modifies from "pedestrian mode" to "mode vehicle ". In" pedestrian mode "the mobile phone only It has active components C2, C3, C4, C5 and C6, which allow it Update your keystore.

To use this invention the user does not have to perform any specific action while driving. Before putting Start the vehicle, enter your destination and route preference Our proposal implies that the device receive and send information automatically, using only the network vehicular and without requiring the driver's collaboration at no time (see Figure 5). When the device detects that the vehicle is traveling at an abnormal speed with respect to the route, generates a warning and sends it to all its neighbors via broadcast With the information received, the device recalculates automatically the recommended route and suggests it to driver.

Several concepts are described below and algorithms proposed as a preferred embodiment of the invention, with the specific objective mentioned.

For module C1 it is proposed as an embodiment particular, that the public identity key is generated as a value decimal of the binary representation corresponding to the submatrix upper triangular symmetric adjacency matrix that It contains the elements corresponding to a Hamiltonian circuit in a graph (see Figure 6).

In module C3 we propose in this embodiment specific, that the variable pseudonym of each node is the hash of the list of IDs of the nodes present in your keystore public at that time. Since this warehouse varies, the pseudonym also varies. In addition, you can perform the checking that the IDs sent in the first step of the authentication correspond to the hash sent in the beacon correspondent.

In module C4 we propose for this realization concrete, as shown in Figure 7, that a node B you want make contact with a node A first request the listing your store IDs at that time, check match of his hash with the pseudonym sent by A in his beacon, and he respond by indicating an X key present at the intersection of both warehouses Then, the demonstration of mutual null knowledge is performs on the public key X so that each node builds to from this key, considering it as a Hamiltonian circuit, a graph G in which X is a solution to the difficult circuit problem Hamiltonian, and sends it to the other node. Then they are done at least two iterations of the demonstration so that in a first step each node sends an isomorphic graph to the other as a commitment token GI to the graph previously sent. Then each node sends to another a random challenge indicating if you want to receive from the other node the isomorphism between both graphs or a Hamiltonian circuit in the isomorphic graph. At the end of the demonstration of null knowledge, both nodes know that they share the public key X, which they use to encrypt using the symmetric encryption described below, and send to the other node its own public identity key. Later exchange their temporary secret keys encrypted with the key public of the other node and finally each uses its own key temporary secret to encrypt with the symmetric encryption described to Then, and send encrypted your keystore, which is contrasted against the pseudonym sent in the beacon and the list of IDs sent in the first authentication step.

For the implementation of module C5 we propose that the warehouse update algorithm described to be used to continuation. In it each node chooses to store in its warehouse those public key certificates of the nodes that most valid certificates have been issued or received, since with that maximize the probability of intersection between warehouses, necessary in module C4. Warehouse certificates and nodes are treated in said algorithm respectively as edges and vertices of a graph

101

\hbox{directamente por el nodo, y -1 para certificados
denunciados por otros nodos.}

For the implementation of module C6 we propose that the dishonest node, instead of directly deleting its public key from the warehouse after improper behavior, reflects its conduct by assigning a negative weight to the edges corresponding to certificates issued or received by it, so that when these certificates receive a negative weight, the vertex will progressively cease to be present in the updated warehouses. This scheme is combined in the warehouse update algorithm with an assignment of weights to edges in the warehouse, according to the following criteria: 2 for certificates issued or received directly by the node, 1 for other certificates, -2 for denounced certificates

 \ hbox {directly by the node, and -1 for certificates
denounced by other nodes.} 

For use in the C7 module, as well as for the secret key encryption contemplated in module C4 we propose a efficient symmetric encryption. This efficiency is essential now that in its first use in module C4 the length of the key used, being a public key, it is generally superior to the set as safe for symmetric ciphers while in its second use in C4, the keystore in general is a very large file. Also in the C7 module itself the file a encrypt containing traffic and road data will be in general very big. Thus, we propose as encrypted symmetric encryption in binary flow using as an encrypted sequence generator the described in Figure 8, which is based on a record of offset with primitive feedback polynomial over GF (2), 1 + c 1 x + c 2 x 2 + ... + c L x x L, of grade L equal to the length of the key used at any time, and fed with the seed formed by said key. The polynomial of Record feedback is given by the primitive polynomial of lower non-zero coefficients and number of said coefficients given by the smallest possible number greater than 0.07 * L, to improve the efficiency. The order of the filtering function is the prime number p closer to L / 2, to ensure large linear complexity. Bliss function includes a linear term corresponding to your order, in addition of a number of terms of each order i = 1, 2, ..., p given by the whole part of L / i, obtained by multiplying successive stages, to achieve pseudo randomness and confusion. To avoid attacks by correlation, the output of said nonlinear filtering is decimated irregularly so that the log output determines in every moment if the corresponding filter output is used or It is discarded. Finally, in order to guarantee an exit stable, a size 4 buffer is included.

As a specific proposal for the implementation of the C8 module, we propose that the verification of matches by aggregation of data be carried out according to a probabilistic protocol based on reactive groups, that is, generated ad-hoc to produce an aggregate package (see Figure 9). There are three situations in which vehicles can be found in relation to an incident: Vehicles that are capable of detecting an obstacle or incident on the road and are responsible for generating the corresponding warning messages; Vehicles that receive warning messages and can confirm that the information is true because they have direct contact with the incident; and Vehicles that receive warning messages but are not able to confirm or deny such information since they are out of range. On the other hand, since in most cases the information generated at a given point is of interest to us outside a certain distance radius from that point, three geographical areas are considered in relation to an incident (see Figure 10): Danger (Z1) or central area of the area where the hazard can be detected directly by the vehicle; Zone of uncertainty (Z2) that surrounds the danger zone and where it is not possible to confirm the information directly but where the decision-making must be quick and efficient because in a short period of time the vehicle will enter the danger zone; and Security Zone (Z3), where the nodes behave following the store-and-carry paradigm gathering evidence about the same danger obtained through different packages. We also propose the establishment of reactive groups when a hazard is detected, so that vehicles cooperate forming groups within their range, in the same geographical cell and generating aggregate information avoiding collisions, delays, network overloads and repetitions of information. With the use of groups we intend to prevent the number of packages generated in a danger zone to warn of a problem grow infinitely, in addition to allowing the reduction of the number of signatures contained in a package. The center of the geographical area corresponds to the location of the existing danger and from it the different groups are generated. In each group there is a leader in charge of building the package and adding the signatures of all the vehicles in his group. Verification of an aggregation message is only performed on those vehicles that are unable to directly verify the information, that is, when a vehicle receives a warning message about an incident that is outside the coverage of its antenna and wants to confirm the authenticity of the message received. The verification carried out by the vehicles depends on the direction of travel and the geographical area in which it is located. In the area of uncertainty, if a vehicle receives an aggregation message containing n signatures, it uses the offset register of length n defined in module C7 fed with the first bit of each of the signatures to generate n bits and verify only the signatures indicated by said exit. In the security zone, the vehicles check a series of signatures contained in the package as described in the previous case, but in addition the vehicles will be able to perform other verifications that provide them with a higher level of reliability on the information received. Thus, being in this area, it is possible to receive several aggregate packages corresponding to the same danger but coming from different groups.

The 8 basic system modules described are adds for the concrete realization, a last module that allows Automatic detection of anomalous road conditions with in order to notify drivers in advance to avoid or Reduce traffic jams

C9. Speed calculation, abnormal traffic conditions and alternative routes

This module uses the information received from a receiver of a global satellite navigation system. Is necessary to be able to use the network in order to help the driving without having to install any infrastructure or in the vehicle or on the road (see Figure 11).

Claims (2)

1. Secure communications system in a spontaneous and self-managed vehicular ad-hoc network comprising: - a module for generating identity keys and digital signature. - a module containing architecture client / server with the possibility of connecting to multiple users to the time - a multicast sending and receiving module Wireless beacons with variable pseudonyms. - a module for mutual authentication of nodes, with exchange of fixed public keys, secret keys temporary, and public key stores based on a scheme interactive challenge-response. - a module for updating the warehouses of public keys - a node reputation module, which deletes from the warehouses to the dishonest nodes, by erasing their public key of certificate stores. - an encrypted data exchange module on static and dynamic elements of the road, through use of a temporary secret key of the issuer. - a data authentication module by checking matches with other messages received through data aggregation.

         \ vskip1.000000 \ baselineskip
      

2. Secure communications system in a spontaneous and self-managed vehicular ad-hoc network according to claim 1 for the reduction of road jams where: - the identity key generation module and digital signature, is based on the generation of the decimal value of the binary representation corresponding to the triangular submatrix upper symmetric adjacency matrix containing the elements corresponding to a Hamiltonian circuit in a graph - the multicast sending and receiving module Wireless beacons with variable pseudonyms is based on the hash of the list of IDs of the nodes present in your keystore public at that time. - the module for mutual authentication of nodes is it is based on a node B that wishes to establish contact with a node A in First, ask for the list of IDs of your store in that moment, check your hash match with the pseudonym sent by A in your beacon, and respond by indicating an X key present in the intersection of both stores. Then, a demonstration of mutual null knowledge about public key X of so that each node builds from that key, considering it as a Hamiltonian circuit, a graph G in which X be a solution to the difficult problem of the Hamiltonian circuit, and what Send to the other node. Then at least two iterations of the demonstration so that in a first step each node sends to the another as an engagement witness an isomorphic graph GI to the graph previously sent. Then each node sends the other a challenge random indicating if you want to receive isomorphism from the other node between both graphs or a Hamiltonian circuit in the graph isomorphic At the end of the demonstration of null knowledge, both nodes know that they share the public key X, which they use to encrypt using the symmetric encryption described below, and send to another node its own public identity key. Later exchange their temporary secret keys encrypted with the key public of the other node and finally each uses its own key temporary secret to encrypt with the symmetric encryption described to Then, and send encrypted your keystore, which is contrasted against the pseudonym sent in the beacon and the list of IDs sent in the first authentication step. - the module for updating the warehouses of public keys is based on using an algorithm on each node choose to store in your store those key certificates public nodes that have issued more valid certificates or received. The certificates and nodes of the store are treated in that algorithm respectively as edges and vertices of a graph. - the node reputation module is based on reflect the behavior of a dishonest node by assigning in the store a negative weight on the edges corresponding to certificates issued or received by him, so that upon receiving said certified a negative weight, the vertex will gradually stop be present in updated stores. This scheme is combines in the warehouse update algorithm with a assignment of weights to edges in the warehouse, according to the following criterion: 2 for certificates issued or received directly by the node, 1 for the remaining certificates, -2 for certificates reported directly by the node, and -1 for certificates denounced by other nodes. - the encrypted data exchange module is based on binary flow encryption using as a generator of coding sequence a declined and buffer nonlinear filtering of a shift register with feedback polynomial primitive on GF (2) of degree L equal to the length of the key used in each moment, fed with the seed formed by said key, and with feedback polynomial given by the polynomial primitive of lower non-zero coefficients and number of said coefficients given by the smallest possible number greater than 0.07 * L. The nonlinear function of filtering has as its order the prime number p closest to L / 2, includes a linear term corresponding to its order, in addition to a number of terms of each order i = 1, 2, ..., p given by the entire part of L / i, obtained by multiplying stages successive The output of said nonlinear filtering is decimated irregularly so that the log output determines in every moment if the corresponding filter output is used or is discarded, entering in the first case in a buffer of size 4. - the data authentication module is based on a data aggregation scheme based on reactive groups in the that each leader is responsible for building the package and adding the signatures of all the vehicles in your group, and where the verification it is done according to a probabilistic protocol that depends on the zone geographical location in which each vehicle is located. - an automatic detection module of anomalous conditions for speed calculation, based on the information received from a receiver of a global system of satellite navigation