ranap ls from ran secmodecntr

8/12/2019 RANAP LS From RAN SecModeCntr

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TSG-SA WG3 (Security) meeting #6 S3-99307Sophia Antipolis, 29thSeptemer ! "stctoer "999

Agen$a %tem&

Source& Ericsson

Title& Draft LS from RAN3: Analysis of distribution of securityparameters beteen !S"-#"$S

'ocument or& %or information

___________________________________________________________________________

Attachment 1:R3-99B77 Security Mode Control procedure for RANAP, Source: Ericsson


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Background

TSG-RAN Working Group 3 meeting #7TSGR3#7(99)D49Sophia Antipoli! "rance! $th-%thSeptem&er 1'''

Agen$a %tem&

Source& ricsson

Title& &roposed liaison statement to SA3' (N)' RAN*

'ocument or& Appro+al

TSG-*A+ Woring Group 3 meeting #Sophia Antipolis, .rance, 2/ - 20 Septemer "999

To& 3!&& SA ,!3

11& RAN ,!*' (N ,!)

Source& 3!&& RAN ,!3

Title& Liaison statement on Security "ode (ontrol procedure

RAN ,!3 as recently appro+ed for te .u RANA& protocol a Security "ode (ontrolprocedure ic corresponds to te traditional ciperin/ mode command control proceduresupplemented it .nte/rity &rotection functionality as mandated by 33)0*

$e details of te appro+ed proposal are contained in te attacment )

RAN ,!3 belie+es tat tis is in line it S3 re1uirements

$e principles of +erification of te 2#E (lassmar4' itout interpretation in #$RAN ereoe+er left open' and S3 is indly ased to comment on te feasibility of suc mecanism

RAN ,!3 also considers tat te said #E (lassmar is a+ailable in te (N itoutassumin/ o tis information is pro+ided to te (N

RAN ,!3 understands also te re-autentication is bein/ discussed in S3' ic mayresult in tat can/in/ of security mode control information may be can/ed in te courseof a communication RAN ,!3 ould lie to no about te status of te relateddiscussions in S3

RAN ,!3 ould lie also to tae opportunity of tis liaison to /et confirmation on ourcurrent assumptions:

- #"$S Encryption Al/oritms 5#EA6 and #"$S .nte/rity Al/oritms 5#.A6 permitted to be

used for security mode control in #$RAN are /i+en by te (N and te selection of icto be used is performed in SRN( $is mecanism is in essence similar to !S"

Attachment 1:R3-99B77 Security Mode Control procedure for RANAP, Source: Ericsson


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ATTA()*+NT 1

TSG-RAN Working Group 3 meeting #7 TSGR3#7(99)B55Sophia Antipoli! "rance! $th, %th o Septem&er 1'''

Agen$a %tem& )03

Source& ricsson

Title& Security "ode (ontrol &rocedure for RANA&

'ocument or& Decision

1 .ntroduction

Ref ! so f"r only includes Cip#er Mode Control "s security function $t is, #o%e&er, " re'uire(ent to"lso #"ndle $nte)rity Protection %#ic# is " ("nd"tory function *see Ref + #is contri.ution t#us

proposes " co((on RANAP procedure for #"ndlin) of .ot# Cip#erin) "nd $nte)rity Protection

/ Background

See App A for ."c/)round infor("tion on t#e $nte)rity Al)orit#(

3/ 0icuion on .ntegrit 2rotection

0it# one co((on 1Security (ode control2 procedure for .ot# cip#erin) "nd inte)rity protection, t#e(ess")e se'uence flo% .elo% descri.es t#e infor("tion tr"nsfer "t initi"l connection est".lis#(ent,

"ut#entic"tion "nd st"rt of inte)rity protection

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ATTA()*+NT 1

E

S$M

+ 1$niti"l 43 (ess")e2 %it# E identity, E cl"ss("r/, 5S$ etc

MSC64R

S8SN

3 Aut#entic"tion "nd /ey )ener"tion

! Stor")e of CN-

: Select "llo%ed $As "nd EAs

SRNC

! RRC connection est".lis#(ent includin) tr"nsfer of

CN- fro( E to SRNC

; Security (ode co(("nd *$A, $5, E cl"ss("r/,

EA, C5, etc

, E cl"ss("r/, EA, etc

!? erify recei&ed (ess")e

9 Security control response

!! Security (ode co(plete

Control of E cl"ss("r/, St"rt

inte)rity, erify (ess")e, etc

1E cl"ss("r/2 cont"ins supported $A "nd EA

Note !:#e net%or/ (ust #"&e t#e 1E security c"p".ility2 infor("tion, %#ic# is p"rt of t#e 1E Cl"ss("r/2,

.efore t#e inte)rity protection c"n st"rt, ie t#e 1E Cl"ss("r/2 (ust .e sent to t#e net%or/ in "nunprotected (ess")e Returnin) t#e 1E Cl"ss("r/2 l"ter on to t#e E in " protected (ess")e %ill )i&eE t#e possi.ility to &erify t#"t it %"s t#e correct 1E Cl"ss("r/2 t#"t re"c#ed t#e net%or/#is l"tter point, "s %ell "s t#e RRC inter%or/ descri.ed .elo%, is yet to .e ")reed in RAN 08+

@et"iled description of t#e flo% ".o&e:

! RRC connection est".lis#(ent includes t#e tr"nsfer fro( E to RNC of t#e CN p"r"(eter to

.e used "s one of t#e input p"r"(eters for t#e inte)rity "l)orit#( #e CN p"r"(eter is storedin t#e SRNC

+ #e E sends t#e $niti"l 43 (ess")e *4oc"tion upd"te re'uest, CM ser&ice re'uest, Routin) "re"upd"te re'uest, etc to t#e rele&"nt CN do("in #is (ess")e cont"ins rele&"nt MM infor("tion"nd "lso t#e E cl"ss("r/ $E, %#ic# includes infor("tion on t#e $A*s "nd EA*s supported .yt#e E #e 5S$ *5ey Set $dentifier is t#e nu(.er "lloc"ted .y t#e CN "t t#e l"st "ut#entic"tionfor t#is CN do("in

3 Aut#entic"tion of t#e user "nd )ener"tion of ne% security /eys *$5 "nd C5 ("y .e perfor(ed Ane% 5S$ %ill t#en "lso .e "lloc"ted

#e CN node deter(ines %#ic# $As "nd EAs t#"t "re "llo%ed to useNote +: #e "ssu(ption is t#"t t#e selection of "l)orit#(s is done in t#e s"(e %"y "s for 8SM#is #"s to .e ")reed %it# RAN 083, RAN 08+ "nd CN 08!

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ATTA()*+NT 1

; #e CN initi"tes inte)rity *"nd possi.le "lso cip#erin) .y sendin) t#e RANAP (ess")e SecurityMode Co(("nd to SRNC #is (ess")e cont"ins "llo%ed $As "nd t#e $5 to .e used $t ("y "lsocont"in t#e "llo%ed EAs "nd t#e C5 to .e used #is (ess")e cont"ins "lso t#e E cl"ss("r/ $Eto .e sent tr"nsp"rently to t#e E

to .e used "nd possi.le "lso t#e EA to .e used Addition"linfor("tion *e) rel"ted to st"rt of cip#erin) ("y "lso .e included Since %e #"&e t%o CNs %it# "n$5 e"c#, t#e net%or/ (ust indic"te %#ic# $5 to use #is is o.t"ined .y includin) " CN typeindic"tor infor("tion in 1Security control co(("nd2 Before sendin) t#is (ess")e to t#e E, t#eSRNC )ener"tes t#e MAC-$ *Mess")e Aut#entic"tion Code for $nte)rity "nd "tt"c#es t#isinfor("tion to t#e (ess")e

At reception of t#e Security control co(("nd (ess")e, t#e E controls t#"t t#e E cl"ss("r/ $Erecei&ed is e'u"l to t#e E cl"ss("r/ $E sent in t#e initi"l (ess")e #e E co(putes MAC-$ on

t#e (ess")e recei&ed .y usin) t#e indic"ted $A, t#e stored CN "nd t#e recei&ed =RES>p"r"(eter #e E &erifies t#e d"t" inte)rity of t#e (ess")e .y co(p"rin) t#e recei&ed MAC-$ %it#t#e )ener"ted MAC-$

9 $f "ll controls "re successful, t#e E co(piles t#e RRC (ess")e Security control co(("ndresponse "nd )ener"tes t#e MAC-$ for t#is (ess")e

!? At reception of t#e response (ess")e, t#e SRNC co(putes t#e MAC-$ on t#e (ess")e #eSRNC &erifies t#e d"t" inte)rity of t#e (ess")e .y co(p"rin) t#e recei&ed MAC-$ %it# t#e)ener"ted MAC-$

!! #e tr"nsfer of t#e RANAP (ess")e Security Mode Co(plete response fro( SRNC to t#e CN

node ends t#e procedure

#e Security (ode co(("nd to E st"rts t#e do%nlin/ inte)rity protection, ie "lso "ll follo%in)(ess")es sent to t#e E "re inte)rity protected #e Security (ode co(("nd response fro( E st"rtst#e uplin/ $nte)rity protection, ie "lso "ll follo%in) (ess")es sent fro( t#e E "re inte)rity protected

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ATTA()*+NT 1

inte)rity protection "l)orit#(s "re not supported2 A SECR$ M@E REEC (ess")e s#"ll "lso.e returned if " CN re'uests " c#"n)e of cip#erin) "nd6or inte)rity protection "l)orit#(s for " E%#en cip#erin) or inte)rity protection is "lre"dy "cti&e for t#"t CN A c"use &"lue s#"ll indic"te t#"tcip#erin) "nd6or inte)rity protection is "lre"dy "cti&e

Note: Re-authentication is being discussed in S3 !hich "a $esu%t in that changing o& a%go$ith"s!i%% be a%%o!ed' Guidance &$o" S3 is needed'

$f t#e r"dio interf"ce Security Control Procedure f"ils, SECR$ M@E REEC s#"ll .e sent toCN %it# " c"use &"lue indic"tin) f"ilure in t#e r"dio interf"ce procedure

#e si)n"llin) flo% of t#e Security (ode control procedure in c"se of unsuccessful oper"tion is s#o%nin =i)ure +

(NRN(

Security7mode7command

Security7mode7re8ect

"igure / Securit *ode (ontrol procedure! unucceul cae/

5/ .normation to traner during Relocation

$nfor("tion needed to continue t#e inte)rity protection "nd cip#erin) "lso "fter " reloc"tion, (ust .etr"nsferred fro( source RNC to t"r)et RNC durin) reloc"tion #e follo%in) infor("tion s#"ll .eincluded:

$A, $5, CN, =RES> for inte)rity protection "nd

EA, C5, CN, BEARER for cip#erin)

Note: .t is %%S eter tis information can all be sent transparently or if some must be

possible to modify by te (N

8/ S+(R.T9 *60+ (6**AN0

.normation element Reerence Tpe

Mess")e type M

$nte)rity Protection $nfor("tion M *!

E Cl"ss("r/ M

Encryption $nfor("tion *!

*! $nte)rity "nd Encryption infor("tion include /ey*s "nd per(itted "l)orit#(sNote ' t is **S !hethe$ N+S in&o$"ation shou%d be inc%uded in this "essage'

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ATTA()*+NT 1

Note ,' The ossibi%it to cihe$ on% so"e o& the R+Bs is **S'Note 3: The need &o$ inc%uding ./ 0%ass"a$1 has to be ag$eed !ith R+N 2G,'

7/ S+(R.T9 *60+ (6*2+T+

.normation element Reerence Tpe

Mess")e type M

C#osen $nte)rity Protection Al)orit#( M

C#osen Encryption Al)orit#(

Note ' t is **S !hethe$ N+S in&o$"ation shou%d be inc%uded in this "essage'

;/ S+(R.T9 *60+ R+


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ATTA()*+NT 1

Appendi= A

#e follo%in) is copied fro( t#e 38 S 33!?+:

#e MS $nte)rity Al)orit#( *$A s#"ll .e i(ple(ented in t#e E "nd in t#e RNC

=i)ure !3 illustr"tes t#e use of t#e $A to "ut#entic"te t#e d"t" inte)rity of " si)n"llin) (ess")e

3$A$5

MAC-$

MESSA8E

C93N

=RES>

Sender

7+ or RN(

3$A$5

BMAC-$

MESSA8E

C93N

=RES>

Recei>er

7+ or RN(

.igure "3& 'eriation o A1-% (or 4A1-%) on a signalling message

#e input p"r"(eters to t#e "l)orit#( "re t#e $nte)rity 5ey *$5, " ti(e dependent input *CN, "r"ndo( &"lue )ener"ted .y t#e net%or/ side *=RES> "nd t#e si)n"llin) d"t" *MESSA8E B"sed ont#ese input p"r"(eters t#e user co(putes (ess")e "ut#entic"tion code for d"t" inte)rity *MAC-$ usin)t#e MS $nte)rity Al)orit#( *$A #e MAC-$ is t#en "ppended to t#e (ess")e %#en sent o&er t#e

r"dio "ccess lin/ #e recei&er co(putes MAC-$ on t#e (ess")e recei&ed in t#e s"(e %"y "s t#esender co(puted MAC-$ on t#e (ess")e sent "nd &erifies t#e d"t" inte)rity of t#e (ess")e .yco(p"rin) it to t#e recei&ed MAC-$

#e input p"r"(eter CN protects ")"inst repl"y durin) " connection $t is " &"lue incre(ented "t.ot# sides of t#e r"dio "ccess lin/ e&ery !? (s l"yer ! fr"(e $ts initi"l &"lue is sent .y t#e user to t#enet%or/ "t connection set-up #e user stores t#e l"st used CN &"lue fro( t#e pre&ious connection"nd incre(ents it .y one $n t#is %"y t#e user is "ssured t#"t no CN &"lue is re-used *.y t#enet%or/ %it# t#e s"(e inte)rity /ey

#e input p"r"(eter =RES> protects net%or/ ")"inst repl"y of si)n"llin) (ess")es .y t#e user Atconnection set-up t#e net%or/ )ener"tes " r"ndo( &"lue =RES> "nd sends it to t#e user #e &"lue

=RES> is su.se'uently used .y .ot# t#e net%or/ "nd t#e user t#rou)#out t#e dur"tion of " sin)leconnection #is (ec#"nis( "ssures t#e net%or/ t#"t t#e user is not repl"yin) "ny old MAC-$s

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ranap ls from ran secmodecntr

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