tag:blogger.com,1999:blog-6828758156183968422.post793712193849480140..comments2024-03-21T14:12:03.742+01:00Comments on How LTE Stuff Works?: LTE NAS: Security Mode CommandKPhttp://www.blogger.com/profile/12785738149524762481noreply@blogger.comBlogger18125tag:blogger.com,1999:blog-6828758156183968422.post-86371966056312669162021-11-21T14:13:41.766+01:002021-11-21T14:13:41.766+01:00I was recently asked a question in an interview: W...I was recently asked a question in an interview: Why is NAS security setup before AS security? Anyone knows the answers?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6828758156183968422.post-14269412242541036172020-06-26T19:27:05.310+02:002020-06-26T19:27:05.310+02:00Hi sir,
Can you tell me e.g of NAS key set identi...Hi sir,<br /> Can you tell me e.g of NAS key set identifier msg comes in to the picture in phone. And what is the use of that msg. What it shows ?Anonymoushttps://www.blogger.com/profile/13620573247972408200noreply@blogger.comtag:blogger.com,1999:blog-6828758156183968422.post-56765197973986634722018-10-22T09:15:41.335+02:002018-10-22T09:15:41.335+02:00what is the difference if KSI is 0 instead of 1what is the difference if KSI is 0 instead of 1Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6828758156183968422.post-54203615796620262812018-03-08T13:13:52.785+01:002018-03-08T13:13:52.785+01:00What could be the possible values for Security Hea...What could be the possible values for Security Header Type in Security Mode complete message, I tried (4) "Integrity protected with new EPS security context" its working fine. Is that correct behaviour or not ?Amit Bajajhttps://www.blogger.com/profile/13017198706788427804noreply@blogger.comtag:blogger.com,1999:blog-6828758156183968422.post-29219823515373763862017-01-17T13:11:14.732+01:002017-01-17T13:11:14.732+01:00For example, if the serving network policy allows ...For example, if the serving network policy allows unauthenticated IMS Emergency Sessions. Refer to 33.401 section 15.2.2KPhttps://www.blogger.com/profile/12785738149524762481noreply@blogger.comtag:blogger.com,1999:blog-6828758156183968422.post-31168995104706654612016-12-27T17:12:02.251+01:002016-12-27T17:12:02.251+01:00at what condition mme does not need to establish n...at what condition mme does not need to establish nas security i.e. not sending SECURITY MODE COMMAND message to ueAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6828758156183968422.post-9579215501043783412016-02-26T15:40:30.528+01:002016-02-26T15:40:30.528+01:00check here: https://www.quora.com/Why-are-there-2-...check here: https://www.quora.com/Why-are-there-2-levels-of-security-at-access-stratum-as-well-as-at-non-access-stratum-in-LTE-as-compared-to-3G-Legacy-systems-which-have-only-AS-level-securityKPhttps://www.blogger.com/profile/12785738149524762481noreply@blogger.comtag:blogger.com,1999:blog-6828758156183968422.post-65744753526154935032016-02-26T06:59:43.147+01:002016-02-26T06:59:43.147+01:00Why there is separate NAS Security procedure in LT...Why there is separate NAS Security procedure in LTE while it is not in WCDMA?<br />Anonymoushttps://www.blogger.com/profile/00309085302939394560noreply@blogger.comtag:blogger.com,1999:blog-6828758156183968422.post-2016897062977254712016-02-26T06:24:51.255+01:002016-02-26T06:24:51.255+01:00Why there is separate NAS Security procedure in LT...Why there is separate NAS Security procedure in LTE while it is not in WCDMA?<br />Anonymoushttps://www.blogger.com/profile/00309085302939394560noreply@blogger.comtag:blogger.com,1999:blog-6828758156183968422.post-32249239548502605012014-12-04T09:07:33.958+01:002014-12-04T09:07:33.958+01:00Can anybody give example of Security Mode Command ...Can anybody give example of Security Mode Command NAS LTE protocol for null integrity algo? Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6828758156183968422.post-51030888317097398492014-09-07T08:07:14.914+02:002014-09-07T08:07:14.914+02:00Can not we merge NAS identity request and authenti...Can not we merge NAS identity request and authentication request into one?<br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6828758156183968422.post-4119547073672408652014-07-03T08:16:00.517+02:002014-07-03T08:16:00.517+02:00Looks like all security protected NAS messages are...Looks like all security protected NAS messages are structured like this. See 8.2.23 of 24.301. After first security header, MAC, sequence number and then NAS message. NAS message for security mode command (8.2.20) by structure contains a security header. <br />I think that before security mode command, all plan NAS messages use this security header.Once security is established, the first security header type needs to be used. <br /><br />I also think that the second security header will never be a non ZERO valueKPhttps://www.blogger.com/profile/12785738149524762481noreply@blogger.comtag:blogger.com,1999:blog-6828758156183968422.post-45831749603913581862014-07-02T16:24:26.638+02:002014-07-02T16:24:26.638+02:00Why is that there are two "Security header ty...Why is that there are two "Security header type" in the message.<br />Will the second one ever have a non zero value ? <br /><br />This question is not only regarding SMC, for any security protected message. <br />Libinnoreply@blogger.comtag:blogger.com,1999:blog-6828758156183968422.post-7530820440274955892012-12-17T16:39:01.511+01:002012-12-17T16:39:01.511+01:00HI,
Which part of the Security Mode Command exam...HI,<br /> Which part of the Security Mode Command example show the eKSI value and how to derive the KASME from the eKSI value?<br /><br />Thank youWhite wolf of Camelothttps://www.blogger.com/profile/16852243158843965011noreply@blogger.comtag:blogger.com,1999:blog-6828758156183968422.post-48697764968666998102012-03-16T10:42:57.126+01:002012-03-16T10:42:57.126+01:00Hi,
eKSI indicates the key KASME. the eKSI may be...Hi,<br /><br />eKSI indicates the key KASME. the eKSI may be either of type KSI-ASME or of type KSI-SGSN for native and mapped security contexts respectively. Please refer to section 4.4.3 in 24.301 for different cases of NAS COUNT handling<br /><br />ThanksKPhttps://www.blogger.com/profile/12785738149524762481noreply@blogger.comtag:blogger.com,1999:blog-6828758156183968422.post-59755706312891669992012-03-13T12:48:07.025+01:002012-03-13T12:48:07.025+01:002 questions:
Q1. Does eKSI indicate which key in ...2 questions:<br /><br />Q1. Does eKSI indicate which key in the KASME-list should be used?<br /><br />Q2. Which is then the NAS COUNT values (for down/uplink) that UE should use? <br /><br />Thanks.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6828758156183968422.post-57869827771820628752012-02-10T10:23:43.258+01:002012-02-10T10:23:43.258+01:00Hi,
The NAS security is mandatory as per 3GPP. Pl...Hi,<br /><br />The NAS security is mandatory as per 3GPP. Please refer to 24.301. Also the security termination points are provided in the TS 36.300 table 14.2-1KPhttps://www.blogger.com/profile/12785738149524762481noreply@blogger.comtag:blogger.com,1999:blog-6828758156183968422.post-85949801448976788522012-02-10T04:57:30.113+01:002012-02-10T04:57:30.113+01:00Is it mandatory to have NAS Security Mode Procedur...Is it mandatory to have NAS Security Mode Procedure as per spec?Anonymousnoreply@blogger.com