Method for processing AK context

Abstract

Base station shares AK context of terminal. When terminal moves between different base stations, PN_D value and PN_U value keeps rise. The method includes steps: first, when switching, object base station needs to obtain PN_U value, which is in use for checking up whether RNG_REQ from terminal is legal, of terminal from service base station; then, terminal keeps PN_D and PN_U; the former expresses minimal value of PN_U to be used at next up going message, the later expresses minimal legal value of PN_D to be appeared in next down going message; when terminal send first message RNG_REQ to object base station if PN_D is larger than PN_U, the method lets PN_U be larger than or equal to PN_D, and then sends RNG_REQ; finally, after receiving first message RNG_REQ from teminal, the object base station carries out message test for PN_U from service base station; after test is passed, setting local PN_D as received PN_U. features are: simple and feasible, solving difficulty for buffering AK.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, in particular to an AK context processing method. Background technique [0002] According to the 802.16 protocol, to communicate with the base station, the terminal must establish the same authorization key context, that is, the AK context. The AK context includes: authorization key (AK), authorization key identifier (AKID), authorization key serial number (AK Sequence Number), authorization key lifetime (AK Lifetime), dual master key serial number (PMK Sequence Number) ), uplink message integrity protection key (HMAC / CMAC_KEY_U), uplink message prevent replay attack packet sequence number (HMAC / CMAC_PN_U, PN_U for short), downlink message integrity protection key (HMAC / CMAC_KEY_D ), downlink message prevent replay attack packet sequence number (HMAC / CMAC_PN_D, PN_D for short), key encryption key (KEK), integrity encryption key (EIK). In this document, "PN" is a general term for ...

AI Technical Summary

Problems solved by technology

[0015] Problem 1: It is difficult to determine the number of AK contexts that need to be cached

The BS side needs to cache all the AK contexts of the MSs that have been here, and the number is even more difficult to determine, possibly tens of thousands

[0016] Problem 2: When any cached AK is lost, it is cumbersome to deal with

In fact, even BS2 itself may not know that AK has been lost, such as BS2 restarted, etc.

[0017] Question 3: If BS2 loses the cached AK and the terminal returns to BS2, the handover will not be successful

[0018] Question 4: If the terminal loses the AK of BS2 and returns to BS2, it can only re-initiate the initial authentication, which reduces the security of the system

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