| Overview |  |
Copyright © 2008 Motivity Telecom Inc.
Authors: Vance Shipley (vances@motivity.ca) [web site: http://www.motivity.ca].
References
Within the security architecture of the 3GPP system there are seven security functions; f1, f1*, f2, f3, f4, f5 and f5* used for authentication and key generation. The operation of these functions is to be specified by each operator and as such is not fully standardised. The algorithms implemented here follow the examples produced on request from 3GPP by ETSI SAGE Task Force and are based on the block cipher Rinjindael now known as Advanced Encryption Standard (AES).
ak() = binary()
A 48 bit anonymity key (AK).
amf() = binary()
A 16 bit authentication management field (AMF).
ck() = binary()
A 128 bit confidentiality key (AK).
ik() = binary()
A 128 bit integrity key (AK).
k() = binary()
A 128 bit subscriber authentication key (K) known only to the HSS and the ISIM/USIM application on the UICC.
mac() = binary()
A 64 bit message authentication code (MAC).
op() = binary()
A 128 bit operator variant algorithm configuration field (OP).
opc() = binary()
A 128 bit key (OPc) derived from the Operator Variant Algorithm Configuration Field (OP) and K known only to the HSS and the ISIM/USIM application on the UICC.
rand() = binary()
A 128 bit random challenge (RAND).
res() = binary()
A 64 bit challenge response (RES).
sqn() = binary()
A 48 bit sequence number (SQN). The management of sequence
numbers is specified in
3GPP TS 33.102 Annex C. The current implementation of
the hss_server module uses sequence
numbers which are not time-based as described in C.1.1.2 and
C.3.2. SQN = SQE || IND where the length of IND is five
bits or in Erlang terms SQN = <<SQE:43, IND:5>>.
| f1/5 | Computes network authentication code MAC-A. |
| f1star/5 | Computes resynch authentication code MAC-S. |
| f2345/3 | Computes response and keys. |
| f5/3 | Computes resynch anonymity key AK. |
| f5star/3 | Computes resynch anonymity key AK. |
| opc/2 | Encode the Operator Variant Algorithm Configuration Field (OP). |
f1(OPc, K, RAND, SQN, AMF) -> MAC_A
Computes network authentication code MAC-A. Takes as input the derived OPc, subscriber key K, random challenge RAND, sequence number SQN and authentication management field AMF. Returns the network authentication code MAC-A.
f1star(OPc, K, RAND, SQN, AMF) -> MAC_S
Computes resynch authentication code MAC-S. Takes as input the derived OPc, subscriber key K, random challenge RAND, sequence number SQN and authentication management field AMF. Returns the resynch authentication code MAC-S.
f2345(OPc, K, RAND) -> {RES, CK, IK, AK}
Computes response and keys. Takes as input the derived OPc, subscriber key K and random challenge RAND. Returns response RES, confidentiality key CK, integrity key IK and anonymity key AK.
Computes resynch anonymity key AK. Takes as input the derived OPc, subscriber key K and random challenge RAND. Returns the anonymity key AK.
Computes resynch anonymity key AK. Takes as input the derived OPc, subscriber key K and random challenge RAND. Returns the anonymity key AK.
Encode the Operator Variant Algorithm Configuration Field (OP). Each operator chooses a value of OP to provide separation between the functionality of the algorithms when used by different operators. The value OPc is used as input for the security functions and is derived from OP and the subscriber key (K).
Generated by EDoc, Dec 29 2008, 15:46:25.