trust management system for opportunistic cloud services

Trust Management System

for

Opportunistic Cloud Servicesk u a d a @ c m i . a a u . d k

E r i c K u a d a ( l e c t u r e r / P h D F e l l o w )

Presentat ion Out l ine

T H I S I S A D A R K B L U E

C I R C L E W I T H T E X T

D e p a r t m e n t o f E l e c t r o n i c S y s t e m s

A A L B O R G U n i v e r s i t y C o p e n h a g e n

I n t ro d u c ti o n

Background

Motivation for the Study

Trust Engineering in Cloud Computing

Overview of Opportunistic Cloud Services

Trust Model for OCS Platforms

Nature of Members and Services

Trust Model in the context of OCS

OCS Trust Management System & Architecture

Trust Model Verification

c o n c l u s i o n

INTRODUCTIONBackground

Par t o f papers f rom PhD study

E . K u a d a a n d H . O l e s e n , “ A S o c i a l N e t w o r k A p p r o a c h t o P r o v i s i o n i n g a n d M a n a g e m e n t o f C l o u d C o m p u t i n g S e r v i c e s f o r E n t e r p r i s e s , ” p r e s e n t e d a t t h e C L O U D C O M P U T I N G 2 0 1 1 , T h e S e c o n d I n t e r n a t i o n a l C o n f e r e n c e o n C l o u d C o m p u t i n g , G R I D s , a n d Vi r t u a l i z a t i o n , 2 0 1 1 , p p . 9 8 – 1 0 4 .

E . K u a d a a n d H . O l e s e n , “ I n c e n t i v e m e c h a n i s m s f o r O p p o r t u n i s t i c C l o u d C o m p u t i n g S e r v i c e s , ” i n 2 0 1 2 8 t h I n t e r n a t i o n a l C o n f e r e n c e o n C o l l a b o r a t i v e C o m p u t i n g : N e t w o r k i n g , A p p l i c a t i o n s a n d Wo r k s h a r i n g ( C o l l a b o r a t e C o m ) , 2 0 1 2 , p p . 1 2 7 – 1 3 6 .

E . K u a d a , H . O l e s e n , a n d A . H e n t e n , “ P u b l i c P o l i c y a n d R e g u l a t o r y I m p l i c a t i o n s f o r t h e I m p l e m e n t a t i o n o f O p p o r t u n i s t i c C l o u d C o m p u t i n g S e r v i c e s f o r E n t e r p r i s e s , ” i n Wo r k s h o p o n S e c u r i t y i n I n f o r m a t i o n S y s t e m s , Wr o c l a v , 2 0 1 2 .

E . K u a d a , K . A d a n u , a n d H . O l e s e n , “ C l o u d C o m p u t i n g a n d I n f o r m a t i o n Te c h n o l o g y R e s o u r c e C o s t M a n a g e m e n t f o r S M E s , ” i n P r o c e e d i n g s o f I E E E R e g i o n 8 C o n f e r e n c e E u r o C o n 2 0 1 3 , U n i v e r s i t y o f Z a g r e b , C r o a t i a , 2 0 1 3 , p p . 2 5 8 – 2 6 5 .



Motivation for the Study

Spare IT Resources at Enterprises and other Organisations

SMEs and even larger Enterprises and organisations need IT resources

It have been difficult or even impossible to make spare IT resources available

to those who need them

Advent of Cloud Computing should make this less difficult

Free Cloud Services Patronage

A need for a platform that supports opportunistic provisioning and utilization of

cloud resources



Opportunistic Cloud Services

Leveraging c loud technologies by enterpr ises to prov ide and ut i l ize c loud serv ices among themselves wi thout enter ing in to

any bus iness agreements

I t is modeled as a soc ia l network of members s t rategica l ly cont r ibut ing and ut i l iz ing Cloud resources



Nature of Members and Services

A n O C S n e t w o r k c o n s i s t s o f a s e t o f s t r a t e g i c m e m b e r s c o n t r i b u t i n g a n d u t i l i z i n g c l o u d s e r v i c e s .

T h e p l a t f o r m c o n s i s t s o f a s e t o f s e r v i c e s e a c h b e l o n g i n g t o a c a t e g o r yE a c h s e r v i c e h a s a n o n - m o n e t a r y c o s t t h a t v a r i e s d y n a m i c a l l y.

T h e s e r v i c e o r r e s o u r c e c o n t r i b u t e d b y a m e m b e r i s o f a c e r t a i n f i n i t e c a p a c i t y a n d t h e r e s o u r c e s t o a p a r t i c u l a r s e r v i c e m a y b e c o n t r i b u t e d b y m u l t i p l e m e m b e r s .

M e m b e r s w i l l n o r m a l l y o n l y c o n t r i b u t e r e s o u r c e s t h a t t h e y h a v e s p a r e c a p a c i t y o f , i . e . t h e y p a c k a g e t h e i r s p a r e I T r e s o u r c e s a s C l o u d s e r v i c e s a n d m a k e t h e m a v a i l a b l e t o t h e O C S p l a t f o r m .

M e m b e r s a r e f r e e t o p r o v i d e a n d d i s c o n t i n u e o n e o r m o r e s e r v i c e s a t w i l l a t a n y p o i n t i n t i m e . T h e y a r e l i k e w i s e f r e e t o u s e o r d i s c o n t i n u e t h e u s a g e o f o n e o r m o r e s e r v i c e s a t w i l l a t a n y p o i n t i n t i m e



OCS Trust Problem

Trus t and secur i t y p rob lems in c loud comput ing a re enhanced in oppor tun is t i c c loud serv i ces

Need to des ign and deve lop a t rus t management sys tem fo r OCS



Trust Engineering in Cloud Computing

Resut l s f rom sys temat i c rev iew o f t rus t eng ineer ing in c loud comput ing

a. Employ ing t rus ted comput ing techno log ies b. Reputa t ion based approaches c. Trus ted th i rd par ty approachesd. The dep loyment mode l a l so p lay a s ign i f i can t par t i n enhanc ing t rus t

be tween serv i ce p rov iders and the i r consumers



Trust Model for OCS Platforms

T h e s u b j e c t i v e n a t u r e o f t h e c o n c e p t o f t r u s t h a s m a d e a s o l i d d e f i n i t i o n e l u s i v e . R e s e a r c h e r s h a v e m o s t o f t e n u s e d t h e t e r m l o o s e l y i n t h e i r w o r kA r i g o r o u s f o r m a l d e f i n i t i o n h a s n o t b e e n a p p l i e d i n m o s t c a s e s

F o r m a l d e f i n i t i o n o r s p e c i f i c a t i o n o f t h e c o n c e p t o f t r u s t i s h o w e v e r n e e d e d f o r e n s u r i n g a u n i f i e d v i e w o f t h e c o n c e p t o f t r u s t i n t h e d e s i g n a n d e n g i n e e r i n g o f t r u s t m a n a g e m e n t s y s t e m s

it T

0u

0

, .c

p pc i c i

U R u

T t R t dR

p

c iT t

( )cU R

,pc iR t

pc iR t



Trust Model for OCS Platforms (cont.)

Leve l o f t rus t o f a serv i ce p rov ider fo r a serv i ce consumer

0

, .p

c cp i p i

U R u

T t R t dR



Trust Model for OCS Platforms (cont.)

S i n c e a p a r t i c u l a r s e r v i c e m a y c o m e i n t o f r u i t i o n a s a c o m b i n a t i o n o f r e s o u r c e s a n d s e r v i c e s f r o m m u l t i p l e p r o v i d e r s , e a c h s e r v i c e ’ s t r u s t l e v e l m u s t b e a s s e s s e d a s a n a u t o n o m o u s e n t i t y e v e n t h o u g h t h i s t r u s t l e v e l i s a f u n c t i o n o f t h e c o m p o s i t e t r u s t l e v e l o f t h e p r o v i d e r s a n d t h e b a s e s e r v i c e s f r o m w h i c h i t h a s b e e n d e r i v e d .

0

, .c

s sc i c i

U R u

T t R t dR



Systematic Review Results

Trust Product ion Approaches

N o r m s a n d i n s t i t u t i o n a l g u a r a n t e e s a t t e m p t t o r e d u c e t h e u n c e r t a i n t y o n t h e b e h a v i o r o f o t h e r a g e n t s b y p r e s c r i b i n g s p e c i f i c a l l o w e d b e h a v i o r a l r a n g e s

I n d i r e c t c u e s a r e a t t r i b u t e s o f a n a g e n t , w h i c h w e h a v e a s s o c i a t e d w i t h c e r t a i n l i k e l y b e h a v i o r s b a s e d o n o u r e x p e r i e n c e , i n t u i t i o n a n d t r a i n i n g .

R e p u t a t i o n a l i n f o r m a t i o n i s i n f o r m a t i o n a b o u t , o r o b s e r v a t i o n s o f a n a g e n t ’ s p a s t b e h a v i o r o n s i m i l a r s i t u a t i o n s

E m p l o y i n g t r u s t e d c o m p u t i n g t e c h n o l o g i e s a n d r e p u t a t i o n b a s e d a p p r o a c h e s

Tr u s t e d t h i r d p a r t y a p p r o a c h e s a n d t h e d e p l o y m e n t m o d e l p l a y a s i g n i f i c a n t p a r t i n e n h a n c i n g t r u s t b e t w e e n s e r v i c e p r o v i d e r s a n d t h e i r c o n s u m e r s .



Systematic Review Results (cont.)

Trusted th i rd par ty based and the reputat ion based approaches comes handy in the context o f t rust engineer ing for OCS envi ronments .

OCS Trust Management System & Architecture



EXPECTATION MANAGER

The expec ta t ion manager i s respons ib le fo r hand l ing the c rea t ion and ma in tenance o f the OCS P la t fo rm pseudo SLA (pSLA) temp la tes , the serv i ce p rov ider ass ignment o f se rv i ces to a par t i cu la r pSLA templa te , and the c rea t ion o f se rv i ce SLA (sSLA) to meet the spec i f i ca t ion o f each serv i ce .



STEP 1



STEP 2



STEP 3



STEP 4



STEP 5



STEP 6



STEP 7



STEP 8



STEP 9



STEP 10



OCS Trust Management ArchitectureDMoM & DMaM

The DMoM is respons ib le fo r de f in ing new t rus t da ta tha t needs to be mon i to red on the OCS p la t fo rm in o rder to accommodate fo r adap t ing the p la t fo rm to fu tu re needs such as when new serv i ce and t rus t va lue ca tegor ies a re needed to be computed

The DMaM is respons ib le fo r de f in ing da ta s to rage po l i c ies such as fo r example loca l s to rage o f t rus t mat r i x by members , s to rage o f member i n te rac t ions by the OCS p la t fo rm, the t ypes o f communica t ion and da ta to be exchanged.

I t a l so dea ls w i th da ta re l i ab i l i t y, secur i t y, recovery i n case o f p rob lems , and ma in ta in ing cons is tency in s i tua t ions o f d i sc repanc ies in da ta f rom mul t i p le sources



OCS Trust Management Architecture (cont.)TAM

The TAM makes the ana lyses o f the t rus t va lues to be computed f rom in fo rmat ion f rom the EM and the ava i l ab le da ta f rom the DMaM. I t then computes the necessary persona l i zed t rus t va lues

Trust Va lues Computat ion Algor i thm1 . I d e n t i f y s e r v i c e d e p e n d e n c i e s f r o m r S L A2 . C o m p u t e t r u s t v a l u e o f t h e s e r v i c e b a s e d o n e q . ( 2 )3 . C o m p u t e t r u s t v a l u e ( b a s e d o n e q . ( 1 ) ) o f e a c h o f t h e s e r v i c e p r o v i d e r s c o n t r i b u t i n g t o t h i s s e r v i c e4 . C o m p u t e c o m p o s i t e t r u s t v a l u e , b a s e d o n



Trust Values Computation Algorithm (cont.)

5. For each serv i ce dependenc ies in s tep 1 , repea t s teps 2 , 3 and 46 . Compute the overa l l compos i te t rus t va lue by app ly ing the appropr ia te dependency leve l we igh t ( ω l ) based on the leve l o f the dependency in the dependency cha in fo r a l l compos i te t rus t va lues as in s tep 4



Trust Model Verification

Attribute value types

Service Identification Service ID & category ID

Service Type / category IaaS & category ID

Availability 50 % uptime

Service support No

Service support type N/A

Maintenance notification Yes

SLA dependencies {}

Service location {}

Security None

Data encryption None

Privacy None

Certification {}

Attributes value types

Service Identification Service ID & category ID

Service Type / category IaaS & category ID


Service support No



SLA dependencies {}

Service location {}

Security Data backup & recovery


Privacy None

Certification {}

Table 1: pSLA template for IaaS Table 2: sSLA created from a pSLA



COMPUTATION OF TRUST VALUES

We compute the t rus t l eve l o f the serv i ce when i s a un i fo rm d is t r i bu t ion w i th parameters

Norma l d i s t r i bu t ion)

)



C o m p o s i t e t r u s t l e v e l w i t h v a r y i n g s e r v i c e w e i g h t , w h e r e t h e t r u s t w o r t h i n e s s o f t h e s e r v i c e a p p r o x i m a t e s a u n i f o r m d i s t r i b u t i o n , a n d t h e t r u s t w o r t h i n e s s o f t h e p r o v i d e r a p p r o x i m a t e s a n o r m a l d i s t r i b u t i o n w i t h t h e s a m e s t a n d a r d d e v i a t i o n a s t h a t o f t h e u n i f o r m d i s t r i b u t i o n



Tr u s t l e v e l a g a i n s t v a r y i n g u s e r u t i l i t y w h e n t h e s e r v i c e a n d t h e s e r v i c e p r o v i d e r h a v e e q u a l w e i g h t o f 0 . 5 i n t h e c o m p o s i t e t r u s t v a l u e

Tr u s t l e v e l a g a i n s t v a r y i n g u s e r u t i l i t y w h e n t h e s e r v i c e h a s a w e i g h t o f 1



Tr u s t l e v e l a g a i n s t v a r y i n g u s e r u t i l i t y w h e n t h e p r o v i d e r h a s a w e i g h t o f 1



OCS Trust Management Architecture (cont.)DSM

The dec is ion suppor t manager i s respons ib le fo r tak ing resu l t s f rom the t rus t va lue computa t ions o f the ana lys i s manager and p resen t ing i t i n a fo rmat tha t s imp l i f y v i sua l i za t ion fo r the users . The user - f r i end ly t rus t va lue represen ta t ion toge ther w i th mak ing recommendat ions on dec is ions to be taken by users shou ld fac i l i t a te the i r dec is ion mak ing p rocess .



OCS Trust Management Architecture (cont.)PGEM

Th is modu le i s respons ib le fo r ensur ing good and accep tab le behav io r on the p la t fo rm. I t app l i es appropr ia te sanc t ions to undes i rab le behav io rs on the p la t fo rm. I t i s there fo re respons ib le fo r ma l i c ious cond i t i ons de tec t ion and the de tec t ion o f SLA v io la t i on , and then tak ing appropr ia te remed ia l ac t i ons such as remov ing o f fend ing serv i ces f rom the p la t fo rm and bann ing o f fend ing users



Conclusion

A m o d e l f o r t h e c o n c e p t o f t r u s t f o r c l o u d c o m p u t i n g e n v i r o n m e n t s

D e s i g n e d a t r u s t m a n a g e m e n t s y s t e m f o r O p p o r t u n i s t i c C l o u d S e r v i c e s

P s e u d o S L A s y s t m e f o r O p p o r t u n i s t i c C l o u d S e r v i c e s

Ve r i f i e d t h e t r u s t m o d e l a n d t h e t r u s t m a n a g e m e n t s y s t e m t h r o u g h t h e s i m u l a t i o n o f t h e c o m p u t a t i o n o f t h e t r u s t v a l u e s w i t h I a a S , a n d S a a S e x a m p l e s .

E v e n t h o u g h o u r t r u s t m a n a g e m e n t s y s t e m s c o n t a i n t h e c o m p l e t e e l e m e n t s , I h a v e f o c u s e d m a i n l y o f t h e m o d e l i n g o f t h e c o n c e p t o f t r u s t f o r t h e O C S p l a t f o r m s a n d t h e t r u s t a n a l y s i s c o m p o n e n t s i n t h e a r c h i t e c t u r e .

T h e o t h e r a s p e c t s r e q u i r e f u r t h e r w o r k i n t e r m s o f t h e i m p l e m e n t a t i o n o f t h e d a t a m o n i t o r i n g a n d d a t a m a n a g e m e n t c o m p o n e n t s .

S e c o n d l y t h e d e c i s i o n s u p p o r t s y s t e m a n d u s a b i l i t y o f t h e p s e u d o S L A t e m p l a t e s i n t h e s y s t e m n e e d s s o m e f u r t h e r w o r k f o r t h e i r v e r i f i c a t i o n .

T h e s e f u r t h e r w o r k s w i l l a l s o r e q u i r e v e r i f y i n g t h e r o b u s t n e s s a n d s c a l a b i l i t y o f t h e t r u s t m a n a g e m e n t s y s t e m .



Thanks



Extra Slides

The level of trust, pc iT t of a service consumer c for a

service provider p in the context of a transaction it T is the

a priori probability that the utility of c will meet or exceed its minimum threshold of satisfaction 0u at the end of transaction

it , given c ’s perceived trustworthiness of service provider p .

Simply stated, trust is the level of confidence of c that the outcome of a transaction with another agent p will be

satisfactory for it. More formally:

0

, .c

p pc i c i

U R u

T t R t dR

, where ( )cU R is the utility

function of service consumer c ; and ,pc iR t - the

trustworthiness of service provider p as perceived by

consumer c in the context of a transaction it T is the a priori

subjective joint probability distribution function of the critical

rating vector pc iR t from the perspective of c .



Table 3: pSLA for SaaS

Attribute value types

Service Identification Service ID &category ID

Service Type / category SaaS & category ID


Service support No



SLA dependencies {}

Service location {}

Security None


Privacy None

Certification {}

Performance (Throughput) 1Kbps

Performance(Response time) 5sec



Trust Production Approaches & Systematic Review Results

N o r m s a n d i n s t i t u t i o n a l g u a r a n t e e s a t t e m p t t o r e d u c e t h e u n c e r t a i n t y o n t h e b e h a v i o r o f o t h e r a g e n t s b y p r e s c r i b i n g s p e c i f i c a l l o w e d b e h a v i o r a l r a n g e s ( w h i c h u s u a l l y c o r r e s p o n d t o s a t i s f a c t o r y o u t c o m e s f o r t h e m a j o r i t y o f t r a n s a c t i o n t y p e s a n d s o c i e t y m e m b e r s ) a n d b y p r o v i d i n g i n s t i t u t i o n s , w h i c h p r e v e n t d e v i a t i o n s o r m a k e s u c h d e v i a t i o n s h i g h l y u n l i k e l y b e c a u s e o f q u i c k d e t e c t i o n a n d e f f e c t i v e s a n c t i o n s

I n d i r e c t c u e s a r e a t t r i b u t e s o f a n a g e n t , w h i c h w e h a v e a s s o c i a t e d w i t h c e r t a i n l i k e l y b e h a v i o r s b a s e d o n o u r e x p e r i e n c e , i n t u i t i o n a n d t r a i n i n g .

R e p u t a t i o n a l i n f o r m a t i o n i s i n f o r m a t i o n a b o u t , o r o b s e r v a t i o n s o f a n a g e n t ’ s p a s t b e h a v i o r o n s i m i l a r s i t u a t i o n s t h a t i s a g g r e g a t e d a n d d i s t r i b u t e d b y m e a n s o f w o r d - o f -m o u t h o r t h r o u g h t r u s t e d t h i r d p a r t i e s , s u c h a s c r e d i t r a t i n g a g e n c i e s , c o n s u m e r r e p o r t s , e t c .

E m p l o y i n g t r u s t e d c o m p u t i n g t e c h n o l o g i e s a n d r e p u t a t i o n b a s e d a p p r o a c h e s a r e t w o k e y a p p r o a c h e s t o t r u s t e n g i n e e r i n g i n t h e c l o u d c o m p u t i n g m a r k e t p l a c e . A l s o t r u s t e d t h i r d p a r t y a p p r o a c h e s a n d t h e d e p l o y m e n t m o d e l p l a y a s i g n i f i c a n t p a r t i n e n h a n c i n g t r u s t b e t w e e n s e r v i c e p r o v i d e r s a n d t h e i r c o n s u m e r s .

T r u s t e d t h i r d p a r t y b a s e d a n d t h e r e p u t a t i o n b a s e d a p p r o a c h e s c o m e s h a n d y i n t h e c o n t e x t o f t r u s t e n g i n e e r i n g f o r O C S e n v i r o n m e n t s .

PARAMETERS OF REPUTATIONAL RATINGS

The repu ta t iona l ra t i ngs a re based on the in ten t , i n tegr i t y, capab i l i t y and resu l t s

In tent cons t i tu tes in fo rmat ion abou t dec la red agendas abou t what en t i t i es p romise to p rov ide th rough the i r se rv i ces .

In tegr i ty cons t i tu tes in fo rmat ion abou t hones ty ; th i s i s a measure o f , to what ex ten t en t i t i es de l i ve r on what they p romised .

Capabi l i ty cons t i tu tes in fo rmat ion abou t owned resources (what asse ts par t i es have) Resul ts cons t i tu te i n fo rmat ion about p roduc ts and serv i ces tha t en t i t i es spec ia l i zed in th rough cons is ten t l y de l i ve r ing these p roduc ts and serv i ces sa t i s fac to r i l y to the i r c l i en ts

trust management system for opportunistic cloud services

Documents

cloud technologies

themadvent of cloud

difficult free cloud

set of services

collaborative computing

resources available

social network of members

multiple members