METHOD FOR TRANSMITTING DATA BETWEEN NETWORK NODES

• US 20110158410A1
• Filed: 08/19/2009
• Published: 06/30/2011
• Est. Priority Date: 09/10/2008
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Meyer, Ulrike, Hof, Hans-Joachim, Falk, Rainer
• Granted Patent: US 9,094,818 B2
• Time in Patent Office: Days
• US Class Current: 380/270
• CPC Class Codes: H04L 2209/805 Lightweight hardware, e.g. radio-frequency identification [RFID] or sensor
• CPC Class Codes: H04L 63/1466 Active attacks involving interception, injection, modification, spoofing of data unit addresses, e.g. hijacking, packet injection or TCP sequence number attacks
• CPC Class Codes: H04L 9/0861 Generation of secret information including derivation or calculation of cryptographic keys or passwords
• CPC Class Codes: H04L 9/3242 involving keyed hash functions, e.g. message authentication codes [MACs], CBC-MAC or HMAC
• CPC Class Codes: H04W 12/02 Protecting privacy or anonymity, e.g. protecting personally identifiable information [PII]
• CPC Class Codes: H04W 12/033 of the user plane, e.g. user's traffic
• CPC Class Codes: H04W 12/037 of the control plane, e.g. signalling traffic
• CPC Class Codes: H04W 12/102 Route integrity, e.g. using trusted paths
• CPC Class Codes: H04W 12/106 Packet or message integrity
• CPC Class Codes: H04W 12/108 Source integrity
• CPC Class Codes: H04W 12/122 Counter-measures against attacks; Protection against rogue devices
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A method transmits data between network nodes of a network in a cryptographically protected manner. The network nodes are, for example, sensor nodes of a wireless sensor network. In the method, in order to transmit the data in a message, a NONCE value is created from a count value which is updated in the transmission of the message and from a constant value which is provided in a shared manner to the network nodes of the network. The data transmitted in the message is then encrypted and decrypted within the network nodes by a cryptographic key and the created NONCE value. The method offers in particular protection against replay attacks while at the same time minimizing the use of resources of the network nodes.

Claims

1-17. -17. (canceled)

18. A method for transmitting data between network nodes of a network in a cryptographically protected manner, comprising:

creating a NONCE value from a count value that is updated when the message is transmitted and from a constant value that is made available to the network nodes of the network in shared fashion; and

encrypting and decrypting the data transmitted in the message by a cryptographic key and the NONCE value.

19. The method as claimed in claim 18, wherein the constant value employed throughout the network is made available to the network nodes of the network by a central management network node.

20. The method as claimed in claim 18, wherein the NONCE value is also created as a function of a transmitting-node address of a transmitting network node that transmits the message to receiving network node of the network.

21. The method as claimed in claim 19, wherein the constant value is conveyed to the network nodes of the network by the central management network node by sending a broadcast message or by sending unicast messages.

22. The method as claimed in claim 19, wherein the constant value is reconfigured by the central management node.

23. The method as claimed in claim 22, wherein the constant value is reconfigured at regular intervals, when a predefined volume of transmitted data has been transmitted, when a predefined number of messages has been transmitted, when a predefined count value has been attained for one of the network nodes, if a predefined event occurs, or when data meeting a predefined condition is transmitted.

24. The method as claimed in claim 20, wherein

the count value is generated by an internal counter of the transmitting network node, and

the NONCE value is created by concatenating the transmitting-node address of the transmitting network node, the constant value, and the count value.

25. The method as claimed in claim 20, wherein

the count value is generated by an internal counter of the transmitting network node,

concatenated data is created by concatenating the transmitting-node address of the transmitting network node, the constant value, and the count value, and

the NONCE value is created through a hash function of the concatenated data.

26. The method as claimed in claim 18, wherein the data transmitted in the message is encrypted and decrypted using a Counter with CBC-MAC (CCM) algorithm.

27. The method as claimed in claim 20, wherein

the count value is a current count value of the transmitting network node,

the message is transmitted with header data and useful data,

the header data comprises the transmitting-node address, a receiving-node address, and the count value, and

the useful data comprises encrypted data.

28. The method as claimed in claim 27, wherein

the receiving network node extracts the transmitting-node address and the count value from the header data,

the receiving network node has an internal counter, which produces a count predict value based on the transmitting-node address,

the receiving network node compares the count value of the transmitting network node with the count predict value produced by the internal counter,

if the count value of the transmitting network node is more current than the count predict value, the receiving network node creates a NONCE value from the count value of the transmitting network node, the shared constant value, and the transmitted transmitting-node address, and

the receiving network node decrypts the data transmitted in the message with the NONCE value created by the receiving network node and a key stored in the receiving network node.

29. The method as claimed in claim 20, wherein the message is transmitted from the transmitting network node to the receiving network node over a radio interface.

30. A network comprising of a plurality of network nodes that transmit data among themselves in messages, each network node comprising:

a NONCE unit to create a NONCE value from a count value that is updated when a message is transmitted and from a constant value that is made available to the network nodes of the network in shared fashion; and

a cryptographic unit to encrypt and decrypt the data transmitted in the message using a cryptographic key and the NONCE value.

31. The network as claimed in claim 30, wherein the network further comprises a central management network node that makes the shared constant value available to the network nodes of the network.

32. The network as claimed in claim 30, wherein the network nodes each have at least one sensor.

33. A non-volatile computer readable storage medium storing a computer program, which when executed by a computer, causes the computer to perform a method for transmitting data between network nodes of a network in a cryptographically protected manner, the method comprising:

creating a NONCE value from a count value that is updated when the message is transmitted and from a constant value that is made available to the network nodes of the network in shared fashion; and

encrypting and decrypting the data transmitted in the message by a cryptographic key and the NONCE value.