Abstract:
A communications apparatus includes a mobile device. The apparatus includes a receiver for receiving at the mobile device a plurality of signals carrying information including received signals which provides randomly varying data related to location of the mobile device. The apparatus includes a random number generator which generates a random number as a function of the data. The apparatus includes a cryptographic key generator which generates a cryptographic key using the random number. A method to establish at a mobile device a random number for cryptographic operations includes the steps of receiving at the mobile device a plurality of signals carrying information including received signals which provides randomly varying data related to location of the mobile device. There is the step of estimating signal entropy for at least one of the received signals in dependence of location where the signals are received by the mobile device. There is the step of selecting the at least one entropy estimated signal having estimated entropy satisfying a predetermined property. There is the step of generating from the at least one entropy estimated signal the random number.
Abstract:
An authentication server and a system and method for managing cryptographic keys across different combinations of user terminals, access networks, and core networks. A Transformation Coder Entity, TCE, (25) creates a master key, Mk, which is used to derive keys during the authentication procedure. During handover between the different access types, the Mk or a transformed Mk is passed between two authenticator nodes (42, 43, 44) that hold the key in the respective access networks when a User Equipment, UE, terminal (41, 51, 52, 53) changes access. The transformation of the Mk is performed via a one-way function, and has the effect that if the Mk is somehow compromised, it is not possible to automatically obtain access to previously used master keys. The transformation is performed based on the type of authenticator node and type of UE/identity module with which the transformed key is to be utilized. The Mk is never used directly, but is only used to derive the keys that are directly used to protect the access link.
Abstract:
A method of facilitating the lawful interception of an IP session between two or more terminals 12,13, wherein said session uses encryption to secure traffic. The method comprises storing a key allocated to at least one of said terminals 12,13 or to at least one of the subscribers using one of the terminals 12,13, at the terminal 12,13 and at a node 5,8 within a network 1,6 through which said session is conducted, or a node coupled to that network. Prior to the creation of said session, a seed value is exchanged between the terminal 12,13 at which the key is stored and said node 5,8. The key and the seed value are used at both the terminal 12,13 and the node 5,8 to generate a pre-master key. The pre-master key becomes known to each of the terminals 12,13 involved in the IP session and to the network node 5,8. The pre-master key is used, directly or indirectly, to encrypt and decrypt traffic associated with said IP session.
Abstract:
There is disclosed a method, and a communication system, and a communication node for implementing the claimed method, for attempting to enhance legitimacy assessment and thwart a man-in-the middle or similar false-location attack by evaluating the topology of a communication-session requesting node relative to the proposed communication path through a network between the requesting node and the requested node. Upon receiving the request,a PRD (Prefix Reachability Detection) protocol is initiated, either after or during a secure key exchange, if any, which if performed preferably includes an ART (address reachability text). The PRD is executed by sending a message to the communication node challenging the location-authenticity of the requesting device. The communication node, which may be for example an access router through which the requesting node accesses the network, determines if the requesting node is positioned behind the communication node topologically, and reports the result to the requested node. The requested node may then make a decision on whether to permit the communication. If so, the PRD may be repeated one or more times while the communication session is in progress.
Abstract:
A method and apparatus for establishing a cryptographic relationship between a first node (102) and a second node (101) in a communications network. The first node receives at least part of a cryptographic attribute of the second node, uses the received at least part of the cryptographic attribute to generate an identifier for the first node. The cryptographic attribute may a public key belonging to the second node, and the identifier may be a Cryptographically Generated IP address. The cryptographic relationship allows the second node to establish with a third node that is entitled to act on behalf of the first node.
Abstract:
A method of improving privacy by hiding, in an ordered sequence of messages M[x(1), D(1)], M[x(2), D(2)], etc, communicated between a first and at least one second party sharing a key k, metadata x(i) descriptive of message processing, wherein D(i) denotes payload data. The method comprises the first and the second party agreeing on a pseudo random mapping depending on a shared key k, F k , mapping at least x(i) to y(i), and the first party modifying the messages by replacing x(i) by y(i) in each message M(x(i), D(i)). The first party then transmits the modified messages maintaining their original order, and on reception of a message M(y(m), D), the second party uses a mapping G k to retrieve position m of received value and the original value x(m).
Abstract:
A method of processing binary data representing field elements of an odd-characteristic finite field GF(pk) is described. The method comprises storing binary data representing at least a portion of a field element of an odd-characteristic finite field GF(pk) in a register, p being an odd prime number, the field element comprising k coefficients in accordance with a polynomial-basis representation, the binary data comprising plural groups of data bits, wherein each group of data bits represents an associated one of the k coefficients. The method also comprises executing at least one operation on contents of the register such that the plural groups of data bits are processed in parallel. An apparatus comprising a memory and a processing unit coupled to the memory to carry out the method is also described.