Abstract: A key exchanging apparatus transmits the contribution data to the plurality of counterpart apparatuses, generates a signer contribution confirmation signature with respect to a contribution data set including all the contribution data received from the plurality of counterpart apparatuses, generates auxiliary data and auxiliary data validity certification sentence from the contribution data set and the contribution random number, transmits the auxiliary data, the auxiliary data validity certification sentence and the contribution confirmation signature to the plurality of counterpart apparatuses, verifies validity of auxiliary data by using the counterpart identifier set, the counterpart public key set, the contribution confirmation signature set including the data received from the plurality of counterpart apparatuses, the auxiliary data set and the auxiliary data validity certification sentence set, and generates a public key from the contribution data set and the auxiliary data received from the plurality

Abstract: A method for aggregating data in a network, particularly in a wireless sensor network, wherein the network (1) includes a plurality of sensor nodes (Ni) to measure data and at least one sink node (S) at which the data measured by the sensor nodes (Ni) are aggregated, and wherein each sensor node (Ni) encrypts its measured data with a key k and forwards the result towards the sink node (S), is characterized in that, in the context of a key distribution within the network (1), a master key K is chosen, and that the master key K is autonomously split up by the network (1) into individual keys ki to be used by the sensor nodes (Ni) for encrypting measured data, with the sum of all individual keys ki being equal to the master key K.

Abstract: In a method for distributing keys for encrypted data transmission in a sensor network, nodes store a subset of keys from a set of keys. A sink node triggers the key election procedure and sensor nodes choose from a locally broadcasted keyID list, with one key to be stored on each node. All other initially stored keys are subsequently deleted. The process is repeated until the edge of the network is reached. Such key predistribution is suitable for the encryption of reverse multicast traffic to the sink node which is the predominant traffic pattern in wireless sensor networks.

Abstract: A method for establishing a secret key between two nodes in a communication network, in particular in a wireless local area network (WLAN), includes concealment of the fact that a key exchange occurs, one of the nodes—first node (B)—broadcasts one or more packets (Pi) that can be received by the other node—second node (A)—, wherein the packets (Pi) contain each a first key (Ki) and wherein the packets (Pi) are each encrypted with a second key (ki) before being sent, the second node (A) randomly chooses one packet (Pm) from the packets (Pi) received and breaks the encryption of the chosen packet (Pm) in order to obtain the first key (Km), and the second node (A) initiates a key exchange protocol, wherein the second node (A) encrypts the message to be sent for initiating the key exchange protocol with the revealed key (Km).

Abstract: A method for operating a wireless sensor network, wherein the sensor network includes a multitude of distributed sensor nodes for sensing data within a pre-definable environment, and wherein the sensor nodes can exchange information via encrypted data transmissions over a radio Channel is—regarding the fact that during the operational phase of the network the Performance of changes in the network, in particular the composition of the sensor nodes that are integrated in the network, is allowed in a flexible way—characterized in that a subset of sensor nodes of the network is manipulated in order to establish a shared secret (x) by transferring a defined information to the sensor nodes of the subset over a secure out of band (OOB) Channel.

Abstract: Method to transmit data in an ad hoc network or a sensor network with the network comprising a multitude of sensor nodes to sensor data, at least one aggregator node to aggregate the sensored data of at least a subset of the sensor nodes, and at least one sink node to collect the data of the aggregator node is characterized in—regarding a high level of security against attacks from outside while transmitting data, and regarding an economic energy consumption—that the sensored data is encrypted at the sensor nodes, that the encrypted data is transmitted to one of the aggregator nodes, that at the aggregator node an aggregation function is executed on the encrypted data, and that the result of the aggregation function is transmitted to the sink node and decrypted there.

Abstract: A method for managing data in a preferably non real-time sensor network, wherein the network comprises a multitude of sensor nodes to sense data, wherein the network is divided into clusters with each consisting of several sensor nodes, wherein within each cluster a sensor node acts as aggregator node to aggregate the sensed data of the rest of the sensor nodes of the cluster, and wherein always a pre-configurable number of neighbored clusters are combined to groups and the data aggregated within a cluster are stored by the aggregator node of the cluster itself and in addition by another aggregator node of a cluster of the respective group is characterized in that the data is encrypted with homomorphic methods before being stored persistently.

Abstract: A method for distributing keys for encrypted data transmission in a preferably wireless sensor network. Initially nodes store a subset of keys from a set of keys. A powerful sink node located in the centre of the wireless sensor triggers the key election procedure and sensor nodes choose from a locally broadcasted key-ID list one key to be stored on each node. All other initially stored keys are subsequently deleted. The process is iteratively until the edge of the network is achieved. Such key pre-distribution suits for the encryption of reverse multicast traffic to the sink node which is the pre-dominant traffic pattern in wireless sensor networks.

Abstract: A method for transmitting messages of at least one entity that creates messages to a target entity, wherein the messages sent by the creating entity are signed, wherein the individual entities are interconnected over a network, and wherein at least one aggregation entity, which combines several messages to an aggregated message, is provided in the network is—regarding a possibly simple and secure authentication—characterized in that by the aggregation entity a signature of the aggregated message is created in such a way that the aggregated message and the individual messages contained in the aggregated message can be verified at the target entity by knowing the aggregated message and the signature of the aggregated message.

Abstract: A method for authentication of elements of a group, especially for authentication of sensor nodes in a preferably wireless sensor network is disclosed. The group has one specific element—leading element—with which each of the group elements can exchange information and wherein the authentication of the group elements takes place with regard to the leading element. The leading element sends an authentication request to the group elements wherein the authentication request is the same for all the group elements. The group elements each send authentication responses—based on the authentication request—to the leading element, with the authentication responses being different for each group element.

Abstract: Method to transmit data in an ad hoc network or a sensor network with the network comprising a multitude of sensor nodes to sensor data, at least one aggregator node to aggregate the sensored data of at least a subset of the sensor nodes, and at least one sink node to collect the data of the aggregator node is characterized in—regarding a high level of security against attacks from outside while transmitting data, and regarding an economic energy consumption—that the sensored data is encrypted at the sensor nodes, that the encrypted data is transmitted to one of the aggregator nodes, that at the aggregator node an aggregation function is executed on the encrypted data, and that the result of the aggregation function is transmitted to the sink node and decrypted there.

Abstract: A method of performing charging and rewarding processes in ad hoc networks with the ad hoc network showing a multitude of active nodes and with one node, which sends or receives packets, is charged costs and a node, which forwards packets within the ad hoc network, is rewarded, is characterized in that charging and rewarding data generated within the ad hoc network is transmitted via an access router to a component of the AAA (authentification, authorization, accounting) architecture for subsequent transmission and/or processing purposes.