THE PREVALENCE OF SAML WITHIN THE EUROPEAN UNION

An Empirical Study

Bernd Zwattendorfer, Thomas Zefferer and Arne Tauber

E-Government Innovation Center (EGIZ), Inffeldgasse 16a, 8010 Graz, Austria

Keywords:

Security Assertion Markup Language, SAML, Authentication, eID, STORK.

Abstract:

Various European countries have set up national eID infrastructures that allow citizens to securely authenticate

at e-Government or e-Banking services. In a converging European society, interoperability between national

eID solutions becomes an important issue. The EU large scale pilot STORK tackles this issue and implements

an interoperability layer that connects national infrastructures. The secure, reliable, and efﬁcient exchange of

identity information is thus a key feature of the STORK interoperability layer. Several protocols exist that

are basically able to implement this feature. In private sector applications, SAML is frequently used for the

exchange of identity and authentication data. To verify whether this protocol has also proven itself in the

public e-Government domain, a survey on existing national eID solutions based on SAML has been carried

out. The survey was based on a comprehensive questionnaire that was sent out to 14 Member States of the

European Union. The collected results revealed that SAML is prevalently used in most national eID solutions

and hence perfectly suitable to build the basis of the STORK interoperability layer.

1 INTRODUCTION

The Internet plays an important role in many aspects

of our daily life. During the past years, an increas-

ing number of security sensitive services have been

mapped to the digital world and are now provided

online. These services have in common that they

usually require a reliable user identiﬁcation and au-

thentication process with a certain level of assurance.

Reliable user identiﬁcation and authentication over

the Internet is no trivial task. For several reasons,

common username and password based authentica-

tion schemes have to be regarded as weak (Kessler,

1997). Hence, security sensitive services usually rely

on stronger two-factor authentication schemes that in-

corporate some kind of cryptographic hardware token

(e.g. smart card, mobile phone) often supported by

public key infrastructures (PKI).

Most European countries use strong authentica-

tion schemes and appropriate PKI solutions for their

national eID infrastructures. National eID infras-

tructures provide citizens a unique electronic ID that

allows for secure and reliable authentication in e-

Government or e-Business processes. A comprehen-

sive overview of existing national eID solutions is

provided by (MODINIS, 2006), (IDABC, 2009) and

(Siddhartha, 2008).

Identity management becomes even more complex

in cross-border scenarios, in which parties from two

or more different countries are involved. During an

authentication process, involved parties need to ex-

change identity and authentication data. Depending

on the authentication process, this data can be consid-

erably complex. It is thus reasonable to have a com-

mon understanding and to appropriately structure the

data to be exchanged according to a well-deﬁned stan-

dard.

The need for a standard that facilitates the struc-

tured exchange of identity and authentication data

has been recognized early. Therefore, the Security

Assertion Markup Language (SAML) (Lockhart and

Campbell, 2008) has been introduced in 2002. It

is an XML based framework, which is heavily used

by the industry and aims to facilitate the exchange

of identity information (Naedele, 2003). Although

SAML is quite popular, also alternative standards and

frameworks exist. Especially WS-Federation has to

be mentioned in this context.

In a converging European economy and society,

country speciﬁc eID solutions hinder the development

of eID based cross-border services. This aspect is em-

phasized in the Digital Agenda for Europe (European

Commission, 2010) and has also been conﬁrmed by

a recent report of the (OECD, 2011) highlighting the

571

Zwattendorfer B., Zefferer T. and Tauber A..

THE PREVALENCE OF SAML WITHIN THE EUROPEAN UNION - An Empirical Study.

DOI: 10.5220/0003938005710576

In Proceedings of the 8th International Conference on Web Information Systems and Technologies (WEBIST-2012), pages 571-576

ISBN: 978-989-8565-08-2

 2012 SCITEPRESS (Science and Technology Publications, Lda.)

need for governments and other stakeholders to cre-

ate solutions for mutual recognition of national digital

identity management approaches. To overcome this

issue, the EU LSP STORK (Leitold and Zwattendor-

fer, 2010) has been started in 2008 as a 3-year project.

STORK aims to establish an interoperability layer for

national eID solutions in order to facilitate eID based

cross-border services. The capabilities of the devel-

oped STORK modules have been demonstrated by

several pilot applications (Tauber et al., 2011) (Knall

et al., 2011).

The (cross-border) exchange of authentication

data is one of the key features of the STORK in-

teroperability framework. The selection of an ap-

propriate standard or framework was therefore one

of the key decisions during the conceptual design.

SAML was known to be a popular industry standard.

However, it was unclear if SAML was also able to

meet the requirements of the public sector, particu-

larly in a cross-border context. To get an overview of

gained experiences with SAML in public sector ap-

plications, an assessment and study has been made

covering all European countries participating in the

STORK project. The basic ﬁndings of this study, the

followed methodology, and consequences of the ob-

tained results are discussed in this paper.

2 SAML

In the current identity and authentication landscape

the Security Assertion Markup Language (SAML)

plays a major role. For being able to follow the em-

pirical research and study that has been carried out in

this paper, a brief introduction to SAML and its archi-

tecture is given.

2.1 Basics

SAML constitutes an XML-based standard that has

been developed by OASIS

and especially designed

for the secure exchange of authentication and autho-

rization data of a given subject. A subject in SAML

terminology deﬁnes the main actor for whom identity

and authentication data needs to be exchanged. Usu-

ally this term concerns a natural person but it can also

be a web service or a system in general (Lockhart and

Campbell, 2008).

According to the general SAML architecture, au-

thentication or authorization data is typically ex-

changed between one identity provider and one or

Organization for the Advancement of Structured Infor-

mation Standards, http:// www.oasis-open.org.

more service providers. The identity provider is usu-

ally responsible for the subject’s authentication and

the issuance of so-called SAML assertions for authen-

tication requesting service providers. A SAML asser-

tion is an XML-based security token, which assures

that a certain subject has been successfully authenti-

cated using speciﬁc means at a certain point in time

and owning speciﬁc attributes if authorization is re-

quired. Service providers that receive such assertions

verify it and grant or deny access to the resources that

have been requested by the subject. In SAML ter-

minology, identity providers are also called asserting

party or SAML authority, service providers can also

be named relying party.

Summarizing, the most important features of

SAML are:

• Single Sign-on (SSO).

• Identity Federation.

• Web Services and other Industry Standards.

2.2 Architecture

SAML highly proﬁts from its modular architecture.

Due to this modularity, various components can be

put together and appropriate solutions for different

use cases can be modeled. In the nested architectural

model statements (as part of assertions) specify the

most detailed and proﬁles the highest abstract level.

The following sub-sections give a brief introduction

into the individual SAML components (Lockhart and

Campbell, 2008).

2.2.1 Assertions

So-called SAML assertions (Lockhart and Camp-

bell, 2008) constitute the core component of SAML.

SAML assertions contain speciﬁc information about a

subject, e.g. related special attributes or information

indicating that the subject has been successfully au-

thenticated. In typical scenarios, assertions are issued

by an identity provider and consumed by a service

provider, which uses the included information for ac-

cess control decisions for the subject.

Basically, three different types of SAML asser-

tions can be distinguished although the wrapping

XML-fragment is common to all of them. A dif-

ferentiation on the assertion is made based on the

statements included. The SAML speciﬁcation distin-

guishes between the following three statements: Au-

thentication Statement, Attribute Statement, Autho-

rization Decision Statement.

Authentication statements are usually created by

an identity provider if a subject has been authenti-

cated successfully. The statement contains informa-

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tion at what point in time and by which means the

subject has authenticated and speciﬁes the validity pe-

riod of the assertion. Attribute statements wrap spe-

ciﬁc attributes belonging to the authenticated subject.

Additionally, authorization statements can give infor-

mation whether the subject is permitted to gain ac-

cess to a certain resource or not. Although autho-

rization statements have especially been designed for

access control, in practice mainly attribute statements

are used for authorization. There is also no strict regu-

lation to use only one statement per assertion. Hence,

different statements can be mixed. However, there is

a limitation to one authentication statement only.

2.2.2 Protocols

SAML Protocols (Lockhart and Campbell, 2008) de-

ﬁne the next layer in this modular architecture. They

specify which assertion is transmitted between two

providers or entities and also deﬁne how this trans-

mission takes place. SAML assertions can be either

pulled from or pushed by an identity provider. If

pulled, the service provider requests an assertion from

the identity provider. If using the push method, the

identity provider sends unsolicited assertions to the

service provider without any further request.

2.2.3 Bindings

SAML Bindings (Lockhart and Campbell, 2008) de-

pict the transport protocol used for carrying the

SAML protocol messages. These protocols remain

untouched by the SAML speciﬁcation and are just

used for transportation. Typical examples for such

transport protocols are HTTP or SOAP web services.

2.2.4 Proﬁles

SAML Proﬁles (Lockhart and Campbell, 2008) com-

bine all inner parts of the modelling architecture to

model certain use cases. The most popular use case

or proﬁle respectively depicts the so-called Web Sin-

gle Sign-On Proﬁle, which enables users SSO by us-

ing web browsers.

3 METHODOLOGY

The main objective and hypothesis, respectively, of

this paper work has been the veriﬁcation to what ex-

tend SAML is used in national eID systems. To

approve this, an empirical study based on question-

naires, which had been distributed to speciﬁc Euro-

pean Union Member States was chosen as adequate

mean.

Before starting any empirical analysis, an agree-

ment on the underlying sample must be obtained. To

achieve the best results, actually no sample should

be taken but in contrast the whole basic population

should be explored. However, in most cases such ex-

plorations are not very economic and are very time

intensive due to a huge population basis. Therefore,

usually a representative sample out of the basic popu-

lation is extracted which saves costs and time but cer-

tainly is not as accurate as a census and hence gives

probabilistic results only.

3.1 Sample Selection

Basically, sample extraction does not deﬁne a triv-

ial task and must be chosen carefully. According to

(Kaya and Himme, 2009), sample extraction must be

carried out by applying the following steps:

1. Determination of the basic population.

2. Determination of the basic selection.

3. Deﬁnition of the sample.

4. Deﬁnition of the selection process.

5. Carrying out the selection.

Mapping these steps to our analysis, the general

basic population would be deﬁned by all countries

over the world (Step 1). However, since probably not

all countries have national eID solutions deployed, we

limit the basic population to countries that have al-

ready national eID infrastructures in place or are plan-

ning to do so in the next years (Step 2). Because

for the whole world this would also not be a feasi-

ble and trivial approach, the basic selection is nar-

rowed down to European countries as a sample set

(Step 3). Out of this sample set, the actual sample

has to be chosen and analyzed. In theory, a sample

should be selected completely random. However, in

practice this usually can never be achieved and one’s

sights must be lowered. Hence, the underlying sam-

ple of an empirical study can be selected on various

aspects. For that, several approaches exist, e.g. based

on random or non-random selection. For our analy-

sis, an approach based on convenience sampling

was

chosen (Step 4). This approach has been chosen due

to practical aspects. Since this work was carried out

within the STORK project, all countries participating

in this LSP were chosen for building a representative

sample

(Step 5). In fact, this ﬁnal sample consisted

of 14 countries, involving Austria, Belgium, Estonia,

France, Germany, Italy, Luxembourg, Netherlands,

Convenience sampling deﬁnes a non-random selection

method where elements of the sample are readily available

or nearby. (Black, 2010).

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Portugal, Slovenia, Spain, Sweden, United Kingdom,

and Iceland (as the only non EU country).

3.2 Structure of the Questionnaire

After selecting the appropriate sample and before be-

ing able to do any analysis, information and data must

be gathered. This section brieﬂy describes the struc-

ture of the questionnaire that had been sent out to the

STORK partners for information gathering. Actually,

the questionnaire can be divided into two parts. The

ﬁrst part containing administrative questions request-

ing contact details in case any questions arose as well

as motivating the questionnaire, the second part ask-

ing speciﬁc questions to SAML implementations and

speciﬁcations. Besides contact details, the adminis-

trative part concluded with a short introduction into

SAML. This introduction overviewedthe architecture

and the most important parts of SAML giving a con-

cise deﬁnition on the various SAML terms used in the

SAML speciﬁcation to gain a common understanding

amongst all partners.

The actual questionnaire is built upon 17 ques-

tions, involving both closed (offering the recipient

predeﬁned questions) and open (possibility to enter

free text) questions. Basically, both general ques-

tions as well as more technically detailed questions

regarding SAML were asked. For instance, gen-

eral questions concerned the national eID system and

its use of SAML, or practical details or issues dur-

ing SAML adoption. In addition, detailed questions

speciﬁcally focused on the SAML speciﬁcation, e.g.

asking which SAML versions are deployed or - re-

garding to the SAML architecture - which protocols,

bindings, or proﬁles are in use. The order of the de-

tailed questions were aligned according to the natu-

ral nesting of the SAML architectural components,

hence a top-down approach was followed. According

to this approach, questions regarding to the use cases

(SAML proﬁles) were asked ﬁrst. Referring to section

2, SAML proﬁles constitute the outermost part of the

architectural model. Following the intuitive structure

of this model, questions concerning bindings, proto-

cols and assertions as the innermost part were stated

next. In the following, details on the assertion struc-

ture or whether parts are signed or encrypted were

questioned. At the end, open questions rounded up

the questionnaire in order to give the participants the

Please note that this work has already been carried out

during the ﬁrst project phase of STORK when no Member

State enlargement had been deﬁned. An enlargement of ad-

ditional ﬁve Member States was negotiated in the second

year of the project phase only, hence those ﬁve countries

are not part of our analysis.

possibility to provide hyperlinks for further informa-

tion beyond the scope of this questionnaire.

4 RESULTS

This section reports on the results extracted and syn-

thesized from the returned questionnaires. The com-

plete analysis and evaluation of the questionnaires is

based on common descriptive statistical methods.

All of the sent out questionnaires were returned,

thus we could rely on a response rate of 100% for our

analysis

. Although a sample of 14 countries does not

represent all European Union Member States, at least

a very good approximation can be given for the com-

plete EU. However, the derived ﬁndings could deliver

a complete picture of the use of SAML in the STORK

Member States and built a fundamental basis for the

standards chosen in the STORK speciﬁcation.

In general, 11 out of 14 countries are either using

SAML (Austria, Belgium, France, Portugal, Spain,

UK, and Iceland) or are planning to do so (Italy, the

Netherlands, Slovenia, and Sweden) There, SAML is

used in broad context on domestic or regional level

in the national eID systems. This ﬁnding corresponds

to a quota of about 80% of SAML using countries

and can be seen as an evidence for the prevalence of

SAML in the European Union. The only countries of

the interviewed sample that do not rely on SAML are

Estonia, Germany and Luxembourg.

The ﬁrst country deploying SAML in its national

eID infrastructure has been Austria which has started

the adoption of SAML (version 1.0) already in 2002.

Belgium and France were next having started in 2003

and 2004 respectively (version 1.0 and 1.1). A cou-

ple of countries have been deploying SAML in 2008,

mostly based on the SAML version 2.0. Most coun-

tries rely on national guidelines for their SAML im-

plementation. However, there exists also a number

of countries which have deployed SAML on regional

level only (e.g. Catalonia in Spain) and hence rely on

sector/application speciﬁc policies.

Besides general questions on the use and the adop-

tion of SAML, more detailed questions affecting the

SAML speciﬁcations were asked to the participating

countries. The aim of those questions was to get in-

sight which out of the box SAML proﬁles, bindings,

or protocols are in place in the Member States. The

dominant version of SAML (planned or already de-

ployed) is the current version 2.0 used by app. 61%

of the asked countries. 23% use SAML version 1.1

and 15% still version 1.0.

Not all questionnaires were completely ﬁlled out

though as some countries do not rely on SAML.

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Concerning the different types of used SAML pro-

ﬁles we limit our evaluation to the proﬁles offered by

SAML version 2.0, as only two proﬁles are standard-

ized in the versions 1.0 and 1.1. SAML 2.0 provides

13 standardized proﬁles in total where only seven are

used over all Member States. The most popular pro-

ﬁle constitutes the Web Browser SSO Proﬁle which

is implemented by six countries. The country, which

bases its eID implementation on the most proﬁles,

is Belgium with eight deployed planned proﬁles (all

SAML versions). All other countries use or plan to

use between one and four standardized proﬁles. The

average proﬁles used per country are 2.66.

In comparison, the average number of SAML

bindings used per country is 2.4. The number of bind-

ings per country is nearly equally distributed, reach-

ing from one to four bindings per country, having

again Belgium leading together with Slovenia. The

most common binding is the HTTP Post Binding with

seven mentions, followed by the HTTP Redirect Bind-

ing with ﬁve, the SAML SOAP Binding with four, and

the HTTP Artifact Binding with three. All those bind-

ings refer to the SAML 2.0 speciﬁcations. As only

few countries still use earlier SAML versions we skip

again a detailed analysis on them.

Additionally, all countries rely on SAML proto-

cols for the transport of SAML assertions. Again,

Belgium uses the most predeﬁned SAML protocols,

namely four. All other countries rely on between one

and three out of the box protocols. The most popular

protocol is the Assertion Query and Request Protocol

in version 2.0 succeeded by the Authentication Re-

quest Protocol, the Artifact Resolution Protocol and

the Single Logout Protocol. Taking proﬁles, bind-

ings, and protocols together, all countries just rely on

predeﬁned SAML components and did not implement

any country speciﬁc solution for SAML adoption.

Digging a little bit deeper into the modular SAML

architecture, after analyzing proﬁles, bindings, and

protocols we evaluated the use of SAML assertions

and its statements. Nearly all responding countries

(87.5%) have an authentication statement included

in their assertion (except Austria). Thereby, for au-

thentication different authentication methods are in-

voked in all countries, reaching from simple user-

name/password mechanisms to more secure and high

sophisticated smart card and PKI based solutions. In

contrast to that, all participating countries include at

least one attribute statement in their assertion. Bel-

gium, Italy and the UK even include more than one.

In our questionnaire, we also asked which kind of and

how many attributes are wrapped in an attribute state-

ment. Most countries use SAML assertions only for

identiﬁcation of natural persons (in Austria, France,

and Spain legal persons can also be authenticated in

the national eID infrastructure), hence the most com-

mon attributes are a unique/sectoral identiﬁer, ﬁrst

name, last name, and date of birth. Regarding the

maximum number of attributes (mandatory or op-

tional) within an attribute assertion, UK’s assertion

can take up to nine attributes, Autria’s seven, and

Italy’s six. The average number of attributes in one

assertion is 4.75.

Concerning section 2, besides authentication and

attribute statements also authorization statements can

be incorporated in a SAML assertion. However, this

feature is rarely used amongst the participating coun-

tries. Only Belgium is planning to regulate access

control using this SAML possibility.

All Member States take care about the security of

the identiﬁcation and authentication data transmitted.

In fact, all countries sign their SAML assertion using

XML-DSig as signature syntax and processing algo-

rithm. However, in contrast no country actually en-

crypts the assertion. Also no encryption algorithm is

used for encrypting single attributes. To additionally

improve security, SAML assertions have only a cer-

tain period of validity. However, this validity period

greatly varies between the Member States, reaching

from 5min (Belgium, France, and Spain) to a couple

of hours (Iceland and UK) or even severaldays (Italy).

5 CONCLUSIONS

The aim of the work carried out in this paper was to

prove if SAML is also a dominant standard for ex-

changing identiﬁcation and authentication data in na-

tional eID concepts across the European Union. To

verify this, a questionnaire containing general ques-

tions to the national eID infrastructure and addition-

ally more detailed questions regarding the structure

of SAML components (proﬁles, bindings, protocols,

and assertions) was sent out to all 14 partners of the

STORK project in its early phase. All partners repre-

senting a Member State replied to this questionnaire,

hence the evaluation of those questionnaires is based

on a response rate of 100%. Based on these results

and ﬁndings, SAML can be seen as an important stan-

dard in the ﬁeld of eID across Europe. The prevalence

of SAML amongst the interviewed Member States led

also STORK to set up its interoperability framework

for cross-border identiﬁcation and authentication on

SAML 2.0. According to the ﬁndings resulting from

the described empirical study, the Web Browser SSO

Proﬁle and the HTTP Post Binding were chosen as

basic SAML components as they are used most fre-

quently. Although the Assertion Query and Request

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575

Protocol was stated most in the returned question-

naires, the protocol of choice in STORK was the

Authentication Request Protocol. The reason was

because the Authentication Request Protocol espe-

cially focuses on the transfer of secure authentica-

tion data. The SAML assertions transmitted within

STORK contain one authentication statement and one

attribute statement, giving the possibility of includ-

ing a large number of various personal attributes.

Since STORK focuses on authentication of natural

persons only, support for legal persons is not given

yet

. As sensitive data is transmitted within STORK,

the SAML messages are digitally signed but not en-

crypted according to the current status of the partici-

pating Member States. However, to further improve

security the use of the so-called SAML Holder-of-

Key Binding (Lockhart and Hardjono, 2010) has been

speciﬁed.

Although SAML plays an important role in Eu-

ropean eID related applications and authentication

processes, still some gaps could be identiﬁed in this

work. First, although OASIS speciﬁed a high num-

ber of proﬁles, bindings, and protocols, only a small

number of those SAML components are really used

in production. Hence, a couple of ”exotic” speci-

ﬁcations only exist on paper and not in real envi-

ronments. Second, SAML only speciﬁes protocols

for either attribute transfer or authentication. There

does not exist a SAML protocol handling both pro-

cesses in one request/response interaction yet, hence

currently for supporting such a use case the imple-

mentation of two protocols is required. In STORK,

this gap was overcome by using the SAML extension

mechanisms in the protocols and introducing new

XML elements in the Authentication Request Proto-

col (Alcalde-Morano et al., 2011). By doing that,

the exchange of authentication data AND attribute

data for a speciﬁc subject within one request/response

message interaction becomes possible. This gap and

its according solution are currently reported to OASIS

for standardization discussions (Reible, 2011).

Summarizing, the results of our study have shown

that SAML deﬁnes a key component in the European

Union eID landscape when data exchange is required.

Nevertheless, although the SAML speciﬁcation has

been amended and improved over a couple of years,

still lacking capabilities can be found and identiﬁed.

One main objective of the STORK successor project

STORK-2 will be the cross-border recognition of legal iden-

tities (European Commission, 2011).

REFERENCES

Alcalde-Morano, J., Hernndez-Ardieta, J., Johnston, A.,

Martinez, D., Zwattendorfer, B., and Stern, M. (2011).

STORK D5.8.3b Interface Speciﬁcation. STORK

Consortium.

Black, K. (2010). Business Statistics for Contemporary De-

cision Making. Wiley, 6th edition.

European Commission (2010). A Digital Agenda for Eu-

rope, COM (2010) 245. European Commission (EC).

European Commission (2011). ICT Policy Support Pro-

gramme (PSP) Work Programme 2011. European

Commission (EC).

IDABC (2009). eID Interoperability for PEGS: Update of

Country Proﬁles. IDABC.

Kaya, M. and Himme, A. (2009). M¨oglichkeiten der

Stichprobenbildung. In Methodik der empirischen

Forschung. Gabler.

Kessler, G. C. (1997). Passwords - Strengths and Weak-

nesses. In Internet and Networking Security. Auer-

bach.

Knall, T., Tauber, A., Zefferer, T., Zwattendorfer, B.,

Axfjord, A., and Bjarnason, H. (2011). Secure and

Privacy-preserving Cross-border Authentication: the

STORK Pilot ’SaferChat’. In Proceedings of the Con-

ference on Electronic Government and the Informa-

tion Systems Perspective. Springer.

Leitold, H. and Zwattendorfer, B. (2010). STORK: Archi-

tecture, Implementation and Pilots. In ISSE 2010 Se-

curing Electronic Business Processes: Highlights of

the Information Security Solutions Europe 2010 Con-

ference, pages 131–142.

Lockhart, H. and Campbell, B. (2008). Security Assertion

Markup Language (SAML) V2.0 Technical Overview.

OASIS Committee Draft 02.

Lockhart, H. and Hardjono, D. (2010). SAML V2.0 Holder-

of-Key Web Browser SSO Proﬁle Version 1.0. OASIS

Committee Speciﬁcation 02.

MODINIS (2006). The Status of Identity Management in

European eGovernment initiatives. MODINIS.

Naedele, N. (2003). Standards for XML and Web Services

Security. IEEE Computer, 36(4):96–98.

OECD (2011). Digital Identity Management for Natural

Persons: Enabling Innovation and Trust in the Inter-

net Economy - Guidance for Government Policy Mak-

ers. OECD Publishing.

Reible, V. (2011). STORK Results: What’s in it for Indus-

try. Technical report, STORK.

Siddhartha, A. (2008). National e-ID card schemes: A Eu-

ropean overview. Information Security Technical Re-

port, 13(2):46–53.

Tauber, A., Zwattendorfer, B., and Zefferer, T. (2011).

STORK: Pilot 4 Towards Cross-border Electronic De-

livery. In Electronic Government and Electronic Par-

ticipation - Joint Proceedings of Ongoing Research

and Projects of IFIP EGOV and ePart 2011. Springer.

WEBIST2012-8thInternationalConferenceonWebInformationSystemsandTechnologies

576