An Enhancement for Key Management in LTE/SAE X2 Handover Based on Ciphering Key Parameters

Abstract

The security of handover key management in Long Term Evolution(LTE)/System Architecture Evolution(SAE) has been a popular topic in recent years. In this paper we first describe the security architecture and key hierarchy of LTE/SAE, clarifying security requirements of key management in handover. Next, we analyze security of key management in X2 handover(intra-MME handover), and point out the current key management mechanism in X2 handover only satisfy two-hops forward security and one-hop backward security, but not onehop security. And then, aimed at the security vulnerability of lacking one-hop forward security in current X2 handover key management, we proposed a new scheme for key management in X2 handover based on ciphering some key parameters with the local master root key. At last, the proposed new scheme is analyzed under three adversary models. The analysis shows that one-hop forward security and one-hop backward security could be maintained in our new proposal.

Enhancing Security of MME Handover via Fractional Programming and Firefly Algorithm

“…T U , or the MRI, i.e. T R , increases (see Lemmas 1,2,3 and 4). In other words, either a short and frequent KUI or a short MRI causes a waste of signalling overhead, but helps reduce the risk of security breaches with small NEP and OPV.…”

“…[8], [13], [14]. 2 To that end, a mathematical model was developed in [8] to represent the average Number of Exposed Packets (NEP) between two root key updates and the average value of Signaling Overhead Rate (SOR). 3 It was shown that the security of intra-MME handovers can be enhanced by minimising the NEP so as to eliminate the desynchronisation attacks.…”

Efficient Modified Intra-MME Handover Authentication and Key Management Protocol for LTE Networks

“…This loophole has been presented in some recent works [3][4], proposing some solutions to overcome the de-synchronization attack [5][6][7][8], but those could not completely prevent the attack or the proposed solutions were infeasible to implement. Therefore, proposing other solutions to prevent this attack and to maintain the forward key separation during the HO procedure is still needed.…”

On the Handover Security Key Update and Residence Management in LTE Networks

“…In the intra MME handover, i.e. when a user equipment (UE) moves from a source to a target eNodeB 1 within the same MME, the source eNodeB provides the target eNodeB with a new session key 2 to be used after handover. The new key is generated from the current one by either utilising a one-way function, a.k.a.…”

“…Consequently, attacker can either decipher the communications between a genuine eNodeB and a UE or compromise all future keys between 1 A node/access-point provides all radio access protocols. 2 Session keys are used to encrypted messages, i.e. user data and signaling packets, exchanged between a UE and its serving eNodeB [4].…”