Prosecution Insights
Last updated: October 02, 2026
Application No. 17/994,050

KEY OBTAINING METHOD AND APPARATUS

Final Rejection §103
Filed
Nov 25, 2022
Priority
May 26, 2020 — CN 202010454178.9 +1 more
Examiner
HTUN, SAN A
Art Unit
2643
Tech Center
2600 — Communications
Assignee
Huawei Technologies Co., Ltd.
OA Round
4 (Final)
77%
Grant Probability
Favorable
5-6
OA Rounds
0m
Est. Remaining
99%
With Interview

Examiner Intelligence

Grants 77% — above average
77%
Career Allowance Rate
594 granted / 771 resolved
+15.0% vs TC avg
Strong +23% interview lift
Without
With
+22.7%
Interview Lift
resolved cases with interview
Typical timeline
2y 10m
Avg Prosecution
28 currently pending
Career history
800
Total Applications
across all art units

Statute-Specific Performance

§101
6.4%
-33.6% vs TC avg
§103
71.0%
+31.0% vs TC avg
§102
5.1%
-34.9% vs TC avg
§112
6.6%
-33.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 771 resolved cases

Office Action

§103
Detailed Action 1. In this Office Action, in response to the supplemental amendment filed on 05/14/2026, claims 1, 2, 4-7, 11, 12, 14-17 and 21-25 are currently pending in this Office Action. Claim 25 is newly added. Response to Arguments 2. In Remarks, on pages 8-17, applicant presents the arguments for the amended claim limitations “wherein the control plane entity belonging to the first access network device and the user plane entity belonging to the first access network device are different network entities”, “the second key without deriving the second key”, and “the third key without deriving the third key”. However, the amended claim limitations are considered obvious by the rationales found in the newly cited prior art Luo. See step S405 in fig. 12A as explained in the claim rejection section set forth below. Claim Rejections - 35 USC § 103 3. The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102 of this title, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. 4. The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4.Considering objective evidence present in the application indicating obviousness or nonobviousness. 5. Claims 1, 2, 4-6, 11, 12, 14-16 and 21-24 are rejected under 35 U.S.C. 103 as being unpatentable over Lee et al. Pub. No.: US 2019/0037454 A1 in view of Lee et al. Pub. No.: US 2017/0078874 A1, hereinafter, Lee 2, Lee et al. Pub. No.: US 2017/0111339 A1, hereinafter, Lee 3, and Luo et al. Pub. No.: US 2020/0015088 A1. Claim 1 Lee discloses a method (security key derivation for handover in fig. 1-7 & 16-24) comprising: obtaining, by a first core network device (target AMF in fig. 7), a first key (715 in fig. 7, when the source AMF sends refreshed intermediate key to the target AMF, the target AMF obtains the first key; see par. 0107 & 0130, KgNB & KAS-root); performing, by the first core network device, derivation based on the first key to obtain a second key (725 in fig. 7) and a third key (740 in fig. 7), wherein the second key is for performing security processing on control plane signaling of a terminal device (115-b in fig. 7 and source AMF 725 in fig. 7, source AMF is the primary point of control plane signaling with the UEs as explained in par. 0096), and the third key is for performing security processing on user plane data of the terminal device (740 in fig. 7, user plane data through RRC connection as explained in par. 0082). PNG media_image1.png 740 484 media_image1.png Greyscale Although Lee does not explicitly show: “wherein the first key is obtained based on a first root key corresponding to a terminal device; sending, by the first core network device, the second key to a control plane entity belonging to a first access network device, and sending the third key to a user plane entity belonging to the first access network device, wherein the control plane entity belonging to the first access network device and the user plane entity belonging to the first access network device are different network entities, the control plane entity belonging to the first access network device performs control plane signaling communication with the terminal device using the second key without deriving the second key, and, and the user plane entity belonging to the first access network device performs user plane data communication with the terminal device using the third key without deriving the third key”, the claim limitations are considered obvious by the following rationales. Firstly, to address the obviousness of the claim limitations “sending, by the first core network device, the second key to a control plane entity of a first access network device, and sending the third key to a user plane entity of the first access network device”, recall that Lee depicts target AMF for sending second freshness parameter to source AMF and refresh parameters to UE (725 & 740 in fig. 7). In fact, AMF is a control plane entity and UE is obviously a physical layer of a user plane. To advance the prosecution, further evidence is provided herein. In particular, Lee 2 teaches control plane entities SKMF and HSS (300 & 330 in fig. 7) and user plane entities source eNB or GW (fig. 7-8 in view of fig. 3-4). Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify security key derivation for handover of Lee by providing mobility procedure as taught in Lee 2. Such a modification would have provided a mobility management equipment to refresh the security keys based on a UE location so that additional layer of the security is achieved for the cellular network infrastructures as suggested in par. 0006-0008 in Lee 2. Secondly, to consider the amended claim limitation “wherein the first key is obtained based on a first root key corresponding to a terminal device”, initially, it’s to note that claim does not specifically define what are involved in obtaining a first root key such as pre-storing or the receipt from the terminal device, and how the first root key correspond to the terminal device. In fact, the use of root key is intrinsic feature in securing or encrypting wireless communication. Lee and Lee 2 disclose the use of AS root key (par. 0059, 0105 & 0107 of Lee) and a session root key (par. 0106 & 0116). In particular, Lee 3 teaches a device-specific network connectivity root key obtained by a client device and SKMF if AKA procedure is successful (par. 0076, 0085, 0122 & 0128 and fig. 3, 6, 8 & 11). Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify security key derivation for handover of Lee in view of Lee 2 by providing key hierarchy as taught in Lee 3. Such a modification would have provided a security context for different services in a wireless communication system to perform authentication and key agreement procedures for each service so that the individualized recur service could have operated with minimized overhead, i.e., increasing network performance, as suggested in par. 0004-0006 in Lee 3. PNG media_image2.png 748 688 media_image2.png Greyscale Lastly, to address the obviousness of the amended claim limitations “wherein the control plane entity belonging to the first access network device and the user plane entity belonging to the first access network device are different network entities”, “the second key without deriving the second key”, and “the third key without deriving the third key”, recall that Lee explains a first access network device (source AMF in fig. 7) and a target AMF (fig. 7, AMF are two different entities), the use of control plane functions (par. 0071), and user plane communications (par. 0082). What’s more, Lee 2 depicts fig. 3-5 for user plane and control plane existences in different ways. PNG media_image3.png 728 538 media_image3.png Greyscale In particular, Luo teaches wherein the control plane entity belonging to the first access network device and the user plane entity belonging to the first access network device are different network entities (see fig. 2-3, CU-CP, CU-UP and DU are different network entities), the second key without deriving the second key (a second base station receives the target control plane base key without deriving in S405 of fig. 12A), and the third key without deriving the third key (a second base station receives a target user plane base key without deriving in S405 of fig. 12A). Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify security key derivation for handover of Lee in view of Lee 2 and Lee 3 by providing data security processing as taught in Luo to obtain the claimed invention as specified in the claim. Such a modification would have provided a security algorithm for both a UE side and a base station side to derive a user plane key and a control plane key that the data transmission security could have more resistance against an attack or harm with a user plane encryption and a user plane integrity protection key as suggested in par. 0007 of Luo. Claim 2 Lee, in view of Lee 2, Lee 3 and Luo, discloses the method according to claim 1, wherein the control plane entity of the first access network device is located on a side of the first access network device (Lee, AMF in fig. 2 and par. 0111, AMF with HSS, SEAF or AUSF; Lee 2, control plane in HSS, SKMF in fig. 3-4 for side of AMF), and the user plane entity of the first access network device is located on a core network device side (Lee, a base station in fig. 2, i.e., a core network device side; Lee 2, user plane in eNB or GW in fig. 3-4; for these reasons, the combined prior art renders the claim obvious). Claim 4 Lee, in view of Lee 2, Lee 3 and Luo, discloses the method according to claim 1, wherein the method further comprises: PNG media_image4.png 472 658 media_image4.png Greyscale receiving, by the first core network device, an input parameter from a second access network device (Lee, source AMF in fig. 7 sends refreshed intermediate key and then the target AMF generates a target base station key KgNB based on the refreshed intermediate key as explained in par. 0132), wherein the input parameter is for determining the first key (Lee, first key in par. 0132 and steps 715-720 in fig. 7), the second access network device is a source access network device for cell handover of the terminal device (Lee, 705 in fig. 7, handover triggered), and the first access network device is a target access network device for cell handover of the terminal device (Lee, target AMF; Lee 2, see target MME, source MME, targe eNB and source eNB, and handover in fig. 8; and thus, the combined prior art reads on the claim). Claim 5 Lee, in view of Lee 2, Lee 3 and Luo, discloses the method according to claim 4, wherein the input parameter comprises a physical cell identifier (PCI) of a first cell and/or an absolute radio frequency channel number (ARFCN) of the first cell (Lee, PCI in par. 0065; Lee 2, PCI and EARFCN-DL in par. 0098), and the first cell is a target cell for cell handover of the terminal device (Lee, target base station in fig. 2; Lee 2, target eNB in fig. 8; accordingly, the combined prior art renders the claim obvious). Claim 6 Lee, in view of Lee 2, Lee 3 and Luo, discloses the method according to claim 4, wherein the input parameter is comprised in a first handover request message (Lee2, handover request includes the keys as explained par. 0082; handover required 802 in fig. 2), the first handover request message is for requesting to hand over the terminal device to a first cell (Lee 2, handover request in fig. 8 is to handover UE from source eNB to the target eNB), and the first cell is a target cell for cell handover of the terminal device (Lee, fig. 2; Lee 2, target eNB in fig. 8; for these reasons, the combined prior would have been expected one of ordinary skill in the art to perform equally well to the claim). Claim 11, 12, 14-16 Claims 11, 12 and 14-16 are apparatus claims corresponding to method claims 1, 2 and 4-6. All of the limitations of claims 11, 12 and 14-16 are found reciting for structures of the same scopes of the respective limitations in claims 1, 2 and 4-6. Accordingly, claims 11, 12 and 14-16 are considered obvious by the same rationales applied in the rejection of claims 1, 2 and 4-6 respectively set forth above. Claim 21 Lee, in view of Lee 2, Lee 3 and Luo, discloses the communication apparatus according to claim 11, wherein the first access network device is a target base station for cell handover of the terminal device (Lee, a target base station or a target gNB in par. 0129-0132 and fig. 7; Lee 2, target eNB in fig. 8; Lee 3, fig. 6, 8 & 11; accordingly, one of ordinary skill in the art would have expected the combined prior art to perform equally well to the claim; alternatively, rearranging parts involves only routing skill in the art, In re Japikse, 86 USPQ 70 CCPA 1950). Claim 22 Lee, in view of Lee 2, Lee 3 and Luo, discloses the communication apparatus according to claim 11, wherein the first root key is stored by the communication apparatus (Lee 3, 614 in fig. 6, 812 in fig. 8 for storing device-specific network connectivity root key; and thus, the combined prior art reads on the claim). Claim 23 Lee, in view of Lee 2, Lee 3 and Luo, discloses the method according to claim 1, wherein the first access network device is a target base station for cell handover of the terminal device (Lee, a target base station or a target gNB in par. 0129-0132 and fig. 7; Lee 2, target eNB in fig. 8 ; Lee 3, fig. 6, 8 & 11; accordingly, one of ordinary skill in the art would have expected the combined prior art to perform equally well to the claim; alternatively, rearranging parts involves only routing skill in the art, In re Japikse, 86 USPQ 70 CCPA 1950). Claim 24 Lee, in view of Lee 2, Lee 3 and Luo, discloses the method according to claim 1, wherein the first root key is stored by the first core network device (Lee 3, 812 in fig. 8 for a network device storing device-specific network connectivity root key in par. 0122; and thus, the combined prior art renders the claim obvious). Allowable Subject Matter 6. Claims 7 and 17 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. 7. Claim 25 is allowed. The following is an examiner’s statement of reasons for allowance: The prior art of record fails to anticipate or render the claim limitations, as a whole, obvious, particularly: “obtaining, by a first core network device, a first key, wherein the first key is obtained based on a first root key corresponding to a terminal device; performing, by the first core network device, derivation based on the first key to obtain a second key and a third key, wherein the second key is for performing security processing on control plane signaling of the terminal device, and the third key is for performing security processing on user plane data of the terminal device; and sending, by the first core network device, the second key to a control plane entity belonging to a first access network device, and sending the third key to a user plane entity belonging to the first access network device, wherein the control plane entity belonging to the first access network device performs control plane signaling communication with the terminal device using the second key, and the user plane entity belonging to the first access network device performs user plane data communication with the terminal device using the third key; wherein the method further comprises receiving, by the first core network device, an input parameter from a second access network device, wherein the input parameter is for determining the first key, the second access network device is a source access network device for cell handover of the terminal device, and the first access network device is a target access network device for cell handover of the terminal device; wherein the input parameter is comprised in a first handover request message, the first handover request message is for requesting to hand over the terminal device to a first cell, and the first cell is a target cell for cell handover of the terminal device; and wherein the second key is comprised in a second handover request message, and the second handover request message is for requesting to hand over the terminal device to the first cell”, in light of fig. 1-17 depicted in this instant application. Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.” Conclusion 8. Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Contact Information 9. Any inquiry concerning this communication or earlier communications from the examiner should be directed to SAN HTUN whose telephone number is (571)270-3190. The examiner can normally be reached Monday - Thursday 7 AM - 5 PM. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jinsong Hu can be reached on 5712723965. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /SAN HTUN/ Primary Examiner, Art Unit 2643
Read full office action

Prosecution Timeline

Show 3 earlier events
Dec 08, 2025
Response Filed
Feb 02, 2026
Final Rejection mailed — §103
Apr 01, 2026
Response after Non-Final Action
Apr 21, 2026
Request for Continued Examination
Apr 23, 2026
Response after Non-Final Action
May 20, 2026
Non-Final Rejection mailed — §103
Jul 30, 2026
Response Filed
Sep 24, 2026
Final Rejection mailed — §103 (current)

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Prosecution Projections

5-6
Expected OA Rounds
77%
Grant Probability
99%
With Interview (+22.7%)
2y 10m (~0m remaining)
Median Time to Grant
High
PTA Risk
Based on 771 resolved cases by this examiner. Grant probability derived from career allowance rate.

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