Telecom and Informatics 1 Security and Privacy in Distributed Services Trial lecture: Security and Privacy in Distributed Services Richard Torbjørn Sanders

1Telecom and InformaticsSecurity and Privacy in Distributed Services

Trial lecture: Security and Privacy in Distributed

Services

Richard Torbjørn Sanders

NTNU Dept. of Telematics / SINTEF ICT

Richard Torbjørn Sanders

NTNU Dept. of Telematics / SINTEF ICT


Main points

General introduction – no detailed state-of-the-art Define what distributed services are Show how distributed services are modelled in UML Mechanisms at the service session layer

General introduction – no detailed state-of-the-art Define what distributed services are Show how distributed services are modelled in UML Mechanisms at the service session layer


What is a distributed service?

Daily use: Service is something that an organization or system

provides to the public

Within information and communication technology: Several definitions exist

Daily use: Service is something that an organization or system

provides to the public

Within information and communication technology: Several definitions exist


Two kinds of service distribution: Client-server paradigm (web services)

One-way initiatives A service as an interface Restricted

Client-server paradigm (web services) One-way initiatives A service as an interface Restricted

Collaborative services (telecom) Multi-way initiatives A service as a collaboration General

Collaborative services (telecom) Multi-way initiatives A service as a collaboration General

Distributed resources

initiativeresponse

Distributed service logic

two-way initiatives


Definition of service

A service is a collaboration between roles performed by service components (actors) in order to offer functionality to the environment

A service is a collaboration between roles performed by service components (actors) in order to offer functionality to the environment

Actor1 Actor2 Actor3 Actor4 Actor5

Service 3

Service 2

Service 1Service

role

Horizontal composition(within a service)

Vertical composition (within an actor)


Defining services in the Unified Modeling Language (UML)

buyer : Person seller : PersonSale

Actor objectPeter’s phone

plays

Paul’s PC

plays

OrganisationPublic provideruser

Role name : role typeCollaboration

Service

AssociationCollaboration

Role


sd successful sale

DeliveryPayment

Payment

DeliveryPayment

Delivery

: buyer : seller

Request (goods)

Offer (quantity, quality, price)

Order (quantity)

Invoice (amount)

: buyer : seller

Request (goods)


Order (quantity)

Invoice (amount)

Service interactionsSequence diagram

Interactions

Roles

sd successful sale Cash&Carrysd successful sale No Worriessd successful sale Pay On Delivery


Collaborations and roles

Sale

buyer : Person 1 seller : Person 1

Collaboration

Role name and type

Connector


Composite service

Banana distribution

consumer grower

retailer wholesaler buyer

whole : Sale

seller

seller

raw : Sale

buyer

buyer

retail : Sale

seller

Collaboration use


Security and privacy

Threats to citizens, organisations and society Countermeasures

in the context of distributed services Safety is not treated

e.g. poisonous bananas…

Threats to citizens, organisations and society Countermeasures

in the context of distributed services Safety is not treated

e.g. poisonous bananas…


Security and privacy issues

Security: Confidentiality: keeping interactions secret from others Integrity: ensuring that interactions are not hampered with Traceability: documenting that interactions have taken place Availability: are services offered as advertised? Authenticity: are the players who they say they are?

Privacy: the right to choose freely what to expose

Security: Confidentiality: keeping interactions secret from others Integrity: ensuring that interactions are not hampered with Traceability: documenting that interactions have taken place Availability: are services offered as advertised? Authenticity: are the players who they say they are?

Privacy: the right to choose freely what to expose


Layers

Service

Physical Physical

Network Network

Session Session

Application Application

Many security solutions exist

Little done. Focus here!

Security solution not possible


Confidentialitysd successful sale

: buyer : seller

Request (goods)


Keeping interactions secret from others Countermeasures:

Avoidance through encryption at the network level Many standard solutions are available

Challenges: Ease of use for the public

Set up, understand consequences and scope

Keeping interactions secret from others Countermeasures:

Avoidance through encryption at the network level Many standard solutions are available

Challenges: Ease of use for the public

Set up, understand consequences and scope

Eavesdropping


Integritysd order

: buyer : seller

Order (goods)

Invoice (amount)

Ensuring that interactions are not hampered with Countermeasures:

Detection through use of checksums at the network level Avoidance through encryption at the network level

Many standard solutions are available

Ensuring that interactions are not hampered with Countermeasures:

Detection through use of checksums at the network level Avoidance through encryption at the network level

Many standard solutions are available

Changing content


Traceabilitysd order

: buyer : seller

Order (goods)

Invoice (amount)

Ensuring that messages or sessions are not repudiated Countermeasures:

Prevention through digital signatures at the network level Standard solutions are available

Ensuring that messages or sessions are not repudiated Countermeasures:

Prevention through digital signatures at the network level Standard solutions are available

Deny exchange


Availabilitysd successful sale

: buyer : seller

Request (goods)

{no answer}

Ensuring that services are offered as advertised “Denial of service attack”

Countermeasures: Blocking requests from bogus sources at the network level

Not easy to identify bogus sources Role request mechanisms at the session layer

Ensuring that services are offered as advertised “Denial of service attack”

Countermeasures: Blocking requests from bogus sources at the network level

Not easy to identify bogus sources Role request mechanisms at the session layer

Denial of service


Role request pattern - session layer

requesting : ActorTypeA requested : ActorTypeB

ActorStateMachine1. Request (seller, buyer)

3. Confirm (seller)

Buyer

2. Play (seller)

Seller

connector

Requests from illegitimate or infected actors should be discarded Easier than at the network level?

Requests from illegitimate or infected actors should be discarded Easier than at the network level?


Authenticitysd successful sale

: buyer : seller

Request (goods)


Ensuring that role players are who they say they are Countermeasures:

Certificates and authentication protocols at the network level Can be cumbersome

Trusted mechanism at the session layer better?

Ensuring that role players are who they say they are Countermeasures:

Certificates and authentication protocols at the network level Can be cumbersome

Trusted mechanism at the session layer better?

Masquerading/ phishing


Session layer support for authenticity



3. Confirm (seller)

Buyer

2. Play (seller)

Sellerseller

Ensure proper identity of the parties Or support sessions between anonymous (but trusted) parties

Mechanism supported by a trusted session layer

Ensure proper identity of the parties Or support sessions between anonymous (but trusted) parties

Mechanism supported by a trusted session layer

Ensure identities of parties


Emerging security threats

Dynamic role playing (role learning) adds new security threats

Dynamic role playing (role learning) adds new security threats


Role learning pattern

X: Gadget W: SalesServer

Request(seller, buyer)

Confirm(sellerPOD)

BuyerSellerPOD

: ServiceBroker

Lookup(se

llerP

OD, Buye

r)

Result(i

dBuyerP

OD, pro

vider)

Exp

ort

(Buy

erP

OD

)

provider:ServiceRoleProvider

Imp

ort

(idB

uye

rPO

D)

CA’BuyerPOD

buyerBuyerPOD

Is the service role provider to be trusted? Downloading “Trojan horses” - viruses

Is the service role provider to be trusted? Downloading “Trojan horses” - viruses

Request(sellerPOD, buyerPOD)

buyerPOD sellerPOD


Privacy

“The right to be let alone” (1890) “The right to choose freely what to expose” (1967) Protect information concerning persons and organisations

Interests, actions, geographical position Contact lists Role playing capabilities

“People are not concerned about privacy as long as the threat does not become tangible”

Trade-off between privacy and availability / functionality “Amazon recommends…”

“The right to be let alone” (1890) “The right to choose freely what to expose” (1967) Protect information concerning persons and organisations

Interests, actions, geographical position Contact lists Role playing capabilities

“People are not concerned about privacy as long as the threat does not become tangible”

Trade-off between privacy and availability / functionality “Amazon recommends…”


Session layer support for privacy



3. Confirm (seller)

2. Play (seller)

Sellerseller

Mechanism supported by a trusted session layer Mechanism supported by a trusted session layer

Protect private informatione.g. about role playing preferences

Buyer


Conclusion

Security and privacy issues partially dealt with by existing mechanisms

Distributed Services face new threats role learning disclosing role preferences

Trusted session layer support can be beneficial Ensure sessions between legitimate actors Support anonymity when desired Must protect personal data such as role preferences

Trusted third party provider necessary!

Security and privacy issues partially dealt with by existing mechanisms

Distributed Services face new threats role learning disclosing role preferences

Trusted session layer support can be beneficial Ensure sessions between legitimate actors Support anonymity when desired Must protect personal data such as role preferences

Trusted third party provider necessary!

Documents

Telecom and Informatics 1 Security and Privacy in Distributed Services Trial lecture: Security and Privacy in Distributed Services Richard Torbjørn Sanders