Authentication server of a cellular telecommunication network and corresponding UICC
AssigneeThales Dis France SAS
InventorLy Thanh Phan
Life of this patent
Estimating the term…
Abstract
The invention proposes an authentication server of a cellular telecommunication network, the authentication server being arranged for generating an authentication token to be transmitted to a telecommunication terminal, the authentication token comprising a message authentication code and a sequence number, wherein the message authentication code is equal to: MACx=KIdx XOR f1(AMF,SQNx,RAND,K) with KIdx being a key index information in the form of a bias of a MAC equal to: MAC=f1(K,AMF,SQNx,RAND) with f1 being a function, K a key, RAND a random number and SQNx a sequence counter relative to a corresponding key Kx derived from the key K and KIdx, and AMF the content of an authentication management field as defined in 3GPP TS 33.102.
Claims4
An authentication server device of a cellular telecommunication network comprising:
- a memory that stores a Key K,
- wherein said authentication server generates an authentication token and transmits the authentication token to a telecommunication terminal, said authentication token comprising a message authentication code and a sequence number, wherein said message authentication code is equal to:
- MACx=KIdx XOR f1(AMF,SQNx,RAND,K)
- with KIdx being a key index information in the form of a bias of a MAC equal to:
- MAC=f1(K,AMF,SQNx,RAND)
- with f1 being a function, the key K, RAND a random number and SQNx a sequence counter relative to a corresponding key Kx derived from the key K and KIdx, and AMF the content of an authentication management field as defined in 3GPP TS 33.102.
A Universal Integrated Circuit Card (UICC) comprising:
- a memory that stores a Universal Subscriber Identity Module (USIM) application, said USIM application being configured to receive from a telecommunication terminal, with which it cooperates, a message
- AUTNx II RAND
- with RAND a random number and AUTNx being equal to:
- AUTNx=SQNx XOR AK∥AMF∥MACx
- with AK=f5(RAND,K)
- and MACx being equal to:
- MACx=KIdx XOR f1(AMF,SQNx,RAND,K)
- with KIdx being a key index information in the form of a bias of a MAC equal to:
- MAC=f1(K,AMF,SQNx,RAND)
- with f1 and f5 being functions, K a key, SQNx a sequence counter relative to a corresponding key Kx derived from the key K and KIdx, and AMF the content of an authentication management field as defined in 3GPP TS 33.102,
- said application computing a value
- XMAC=f1(AMF,SQNx,RAND,K)
- and a Key Index
- KId=XMAC XOR MACx
- said application verifying that the computed KId matches one of the KIds in a stored white list and, if the match is positive, computing the corresponding key Kx based on the KIdx and computing said key AK, SQNx and
- RESx=f2(Kx,RAND)
- CKx=f3(Kx,RAND)
- IKx=f4(Kx,RAND)
- with ∥ being a concatenation and f2, f3 and f4 being algorithms, and sending RESx, CKx and IKx to said telecommunication terminal.
Dependencies are inferred from the claim text.