Abstract: A method for determining the position of a mobile node applied to a roadside unit (RSU) is provided. The RSU and a plurality of mobile nodes form a communication network of a road. The method includes the steps of: obtaining, by, via at least one sensor, first road information, wherein the first road information provides absolute position distribution information associated with the mobile nodes; receiving, by a communication device, second road information from a first mobile node of the mobile nodes, wherein the second road information provides relative position distribution information associated with the first mobile node and second mobile nodes adjacent to the first mobile node; and determining, by a comparison device, the position of the first mobile node on the road according to the first road information and the second road information.

Abstract: A security certificate management method for a vehicular network node is applied in a vehicular network. A message is received. Whether a certificate in the message is revoked is determined. If the certificate in the message is revoked, a regional certificate revocation list (RCRL) is generated or updated based on the revoked certificate by the vehicular network node, and the RCRL is transmitted into a communication range of the vehicular network node.

Abstract: A method for determining the position of a mobile node applied to a roadside unit (RSU) is provided. The RSU and a plurality of mobile nodes form a communication network of a road. The method includes the steps of: obtaining, by, via at least one sensor, first road information, wherein the first road information provides absolute position distribution information associated with the mobile nodes; receiving, by a communication device, second road information from a first mobile node of the mobile nodes, wherein the second road information provides relative position distribution information associated with the first mobile node and second mobile nodes adjacent to the first mobile node; and determining, by a comparison device, the position of the first mobile node on the road according to the first road information and the second road information.

Abstract: Apparatuses and methods for certificate generation, certificate revocation and certificate verification are provided. The certificate generation and revocation apparatus includes: a key set computation unit receiving a secret value and a hash function set and generating a key set of an entity; a hash function unit generating the hash function set; a certificate generation unit generating certificates corresponding to the public/private key pairs and the key set; a certificate revocation unit acquiring derived secret key corresponding to a revoked certificate set and updating a certificate revocation list; and a certificate revocation list broadcast unit broadcasting the certificate revocation list; wherein the secret value corresponds to a root of a key tree, wherein the key set is generated by leaves of the key tree, wherein each node of the key tree is generated by a randomly selected hash function.

Abstract: A roadside display system, a roadside unit and a roadside display method thereof are provided. The roadside display system includes a sensor, a roadside unit and a display panel. The roadside unit receives object information of an object from the sensor. According to a notifying application and the object information of the object, the roadside unit determines based on an algorithm whether event information is generated, wherein the object information includes coordinate and speed information of the object. The display panel receives the event information from the roadside unit and displays the event information.

Abstract: A security certificate management method for a vehicular network node is applied in a vehicular network. A message is received. Whether a certificate in the message is revoked is determined. If the certificate in the message is revoked, a regional certificate revocation list (RCRL) is generated or updated based on the revoked certificate by the vehicular network node, and the RCRL is transmitted into a communication range of the vehicular network node.

Abstract: A method for vehicle positioning is provided, which includes the steps of identifying at least one vehicle in an image, obtaining identification information of each vehicle from the image, and transforming coordinates of each vehicle in the image into positioning information of the corresponding vehicle according to mapping information. The positioning information is a position of the corresponding vehicle in real world. Precise lane-level vehicle positioning can be achieved based on comparison with the identification information or the positioning information.

Abstract: A certificate management method and a certificate management device are disclosed. The certificate management device includes a key collection computing unit, a certificate revocation unit, and a certificate revocation list broadcast unit. The certificate management method includes determining to at least revoke a first certificate in certificates that are recorded in a key tree and related to an entity, and determining whether a first root node only covers the first certificate and other revoked certificate in the key tree. When the first root node only covers the first certificate and the other revoked certificate, information about the first root node is added to a certificate revocation list. The certificate revocation list is sent to another entity at least.

Abstract: Embodiments of the present invention are directed to methods and systems for generating and revoking, as well as validating, certificates used to protect communications within networks while maintaining privacy protection. In the context of a method, certificate generation and revocation with privacy preservation comprises determining a secret value to be used by a certificate authority and an entity; constructing a key tree based on the secret value, wherein the leaves of the key tree represent derived keys for the certificates for the entity; and generating certificates for the entity based in part on the key tree leaves. The method further comprises determining that one or more of the certificates should be revoked; determining a minimum key node set that covers the certificates to be revoked; adding the minimum key node set to a certificate revocation list; and providing the certificate revocation list to one or more entities. Corresponding apparatuses and computer program products are also provided.

Abstract: Apparatuses and methods for certificate generation, certificate revocation and certificate verification are provided. The certificate generation and revocation apparatus includes: a key set computation unit receiving a secret value and a hash function set and generating a key set of an entity; a hash function unit generating the hash function set; a certificate generation unit generating certificates corresponding to the public/private key pairs and the key set; a certificate revocation unit acquiring derived secret key corresponding to a revoked certificate set and updating a certificate revocation list; and a certificate revocation list broadcast unit broadcasting the certificate revocation list; wherein the secret value corresponds to a root of a key tree, wherein the key set is generated by leaves of the key tree, wherein each node of the key tree is generated by a randomly selected hash function.

Abstract: A certificate management method and a certificate management device are disclosed. The certificate management device includes a key collection computing unit, a certificate revocation unit, and a certificate revocation list broadcast unit. The certificate management method includes determining to at least revoke a first certificate in certificates that are recorded in a key tree and related to an entity, and determining whether a first root node only covers the first certificate and other revoked certificate in the key tree. When the first root node only covers the first certificate and the other revoked certificate, information about the first root node is added to a certificate revocation list. The certificate revocation list is sent to another entity at least.

Abstract: A method for adjusting the frequency of updating certificate revocation list is provided. The method is used in a certificate authority. The method includes: receiving a first information indicating security levels from neighbor certificate authorities in a neighborhood or a central certificate authority; detecting whether the certificate authority has received a signal indicating that a user is using a revoked certificate and generating a second information of a security level; calculating an index value or a set of index values by the first information indicating the security levels of neighborhoods and the second information indicating its own security level; and adjusting the update frequency of updating the certificate revocation list according to the calculated index values or the set of index values.

Abstract: A method for vehicle positioning is provided, which includes the steps of identifying at least one vehicle in an image, obtaining identification information of each vehicle from the image, and transforming coordinates of each vehicle in the image into positioning information of the corresponding vehicle according to mapping information. The positioning information is a position of the corresponding vehicle in real world. Precise lane-level vehicle positioning can be achieved based on comparison with the identification information or the positioning information.

Abstract: A magnet generator has multiple magnets received in a positioning seat of the rotator and a plurality of faces each corresponding to one of the magnets and formed on an outside face of the stator. With such an arrangement, when the generator of the invention is in operation, the generated rotation torque is greatly increased so as to drive a working disk with more power.