Guest at BNR Digital radio on biometrics


biometrie-BNR-MaartenOn August 17th I was a guest at the Dutch BNR news radio station, as part of the weekly BNR Digital broadcast. I was there as expert on biometric authentication. I responded to the questions on the opportunities for biometric authentication in mostly positive manner. I argued that biometric authentication can be a user-friendly second authentication factor. But I also voiced some concerns: not all implementations as done well, liveness detection (presentation attack detection) is and will remain a (if not the) challenge and privacy can be a serious issue.

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Digi2: a PoC app for DigiD



DigiD is the Dutch national digital identity solution for citizens to use e-government services (and online health and pension-related services). It is quite popular actually, in 2015 there where 12 million citizens that had a DigiD, on a population of a bit of 17 millions. Also the amount of logins had increased significant over the year, with over 200 millions logins in 2015. InnoValor did a project in 2015 to make a proof-of-concept app for DigiD that can 1) serve as replacement of SMS as second-factor, 2) can be used with government mobile app and 3) is more secure than current DigiD because it can use the contactless chips in e-passports etc as second factor. We did this project for and with DUO (government organisation responsible for student enrolment, student finance etc), in collaboration with RDW (government organisation responsible for driving licenses, vehicle registration etc) and Logius (government organisation responsible for DigiD).

The below blogpost is written jointly with Jan Kouijzer from DUO and gives details. It is in Dutch and includes links to videos with a demo. It appeared earlier (7 December 2015) on

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FIDO and its place in the eID ecosystem



FIDO stands for Fast Identity Online. FIDO is a new authentication specification that makes it easier to integrate with and re-use non-password authentication means: what-you-have and what-you-are. The specification was published in a v1.0 version last December by the FIDO Alliance, which unites an impressive list of large companies (e.g., Microsoft, Google, Samsung) and smaller authentication companies (e.g., Authasas, Yubico, Nok Nok Labs) to “define an open, scalable, interoperable set of mechanisms that supplant reliance on passwords to securely authenticate users of online services”.

Last Friday (23 January 2015) PIMN organized a seminar on FIDO,  which was fully booked with a waiting list even. In this blogpost I’ll summarize what I learned and what I presented on “FIDO and its place in the identity ecosystem”.

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An NFC app to make your offline identity mobile?


Blogpost by Maarten Wegdam and Martijn Oostdijk

We believe that there is a bright future for the combination of smartphone and digital identity, which we refer to as mobile-centric identity. The question is, of course, how and when, and probably also who (which organisations) will benefit from this.  To contribute to making mobile-centric identity happen, we are experimenting with how we can use a smartphone to get access to our ‘offline identity’, i.e., our passport / ID card. More specifically, we developed an Android app, called NFC Passport reader, that uses NFC to read the chip embedded in a passport / ID Card (aka ePassport). This app is now available from Google Play.

What did we do?

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Context-enhanced authorization: usefulness and feasibility for the banking sector


We did a very interesting  project for a large Dutch bank (Rabobank) and IBM to determine the usefulness and feasibility of Context-enhanced Authorization in the banking sector. We focussed here on employees, and taking their context (location, used device etc) into account for authorization decisions. This would allow the authorization to become more dynamic, and address new trends such as nomadic working (Dutch: Het Nieuwe Werken) and Bring Your Own Device.  An important technology in this project was XACML, for which we used IBM’s tooling (Tivoli Security Policy Manager).  In short the outcome was yes it is useful and yes it is feasible.

Today I presented the project at a XACML seminar, organized by PIMN, CSA, PvIB and SURFnet. I repeat the key take-aways here:

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SIM augmented authentication as alternative for SIM based?


We recently did an assessment of a so-called SIM augmented authentication token, or VASCO’s new DigiPass Nano product to be more specific. We did this for SURFnet, for which we previously also did an assessment of Mobile PKI. We liked Mobile PKI, but it has a big disadvantage: you depend on your mobile network operator to be able to use it (and in the Netherlands they are not deploying this any time soon). This disadvantage is the main motivation to look at SIM augmented tokens. These are, as the term suggests, added to in stead on being ‘inside’ the SIM card.

So what is a SIM augmented authentication token? Physically it is a sticker with an embedded chip that you stick on your SIM card and sits between the SIM card and the mobile phone. The chip stores a secret used for authentication, which is more secure than storing the secret in a ‘normal’ mobile app. This secret is used by an authentication application that is also runs from this chip. This application, from the perspective of the mobile phone, appears to be a normal SIM application, and can work on basically any phone (smart of dumb). The only SIM augmented authentication token that I’m aware of is the above mentioned  DigiPass Nano from VASCO (let me know if you know of others?). The DigiPass Nano implements an event-based one-time-password functionality, i.e., it generated a new code every time the user asks for it.

We did an assessment of the usability, security and business model aspects. Below I copied the conclusions, but the bottom-line is that we believe from a security perspective this is a good alternative to other one-time-password solutions, and it more secure than solutions implemented as a mobile app. The main benefit is that it works on basically any phone (also non-smartphones), and you you can deploy it without needing help (and investments) from your mobile operator. The main disadvantage is the user experience. We did some limited testing with putting the sticker on, which was ok, but the user experience of getting a one-time-password can be troublesome. It requires the user to find SIM applications on their mobile phone, which are often hidden somewhere deep in the menu’s. My estimate is that this usability limitation will need to be addressed for this technology to get acceptance beyond specific enterprise use-cases. Or to put it differently, I’d do very carefull usability optimizations/testing before deploying this to millions of consumers.

This assessment was joint work with my colleague Martijn Oostdijk, see his blog for more details on especially the security aspect. The full report of our assessment is available via the SURFnet website. If you’re looking for a wider perspective on the combination of mobile and digital identity, see this previous blog post on our mobile-centric identity vision.

6 Conclusions

The Digipass Nano uses a form factor that is relatively unique in the authentication token market. It is a SIM augmented token, a thin patch/sticker including an embedded chip that sits between the SIM and the user’s mobile phone. The key advantages of this form factor are:

  • secure storage of credentials under a “security domain” that is distinct from the other stake holders (e.g. mobile operators, handset vendors),
  • while at the same time the ability to use the user-interface of the user’s existing GSM handset,
  • and, potentially, the use of the mobile phone’s GSM or 3G network.

As most users will always carry their mobile phone with them, this means that the token will be present during transactions in many different contexts.

The technology underlying SIM augmentation is based on standards that have existed for a long time, are present in billions of GSM handsets around the world, and have proven to be relatively secure given the threat landscape thus far. The DP Nano does not use all features offered by this technology (it only uses the user interface features, not, e.g., the network features present in GSM 11.14). However, a number of variations of the DP Nano exist (see [10], apparently targeting different markets) which do utilise the networking capabilities of the GSM SIM, and which appear to more strongly bind the token to either handset (“IMEI lock”) or SIM (“IMSI lock”).

On paper, from a technological and security perspective, SIM augmented tokens compare well to other mobile and possession based tokens such as SMS OTP, OTP tokens, mobile soft tokens, and smart cards. As to the security, threats from malware on the handset are minimal as long as the SIM toolkit API interface is properly implemented on the handset.

The user experience may cause some problems for certain groups of users, depending on the issuance and installation process (e.g. whether users are required to install the token themselves). The DP Nano requires the user to navigate through unfamiliar text based menus in order to start up the application when asked by the SP to provide an OTP. This is the most prominent drawback when compared to e.g. the Mobile PKI experience (as described in [8]) where the authentication application on the handset it triggered over the air.

From a business model perspective SIM augmented tokens are interesting as they separate the role of SIM based authentication provider from the role of MNO. Obviously, being the first of its kind and relying on a server side licensing model and proprietary implementation, whether a choice for the DP Nano provides a positive business case when compared to MNO provided SIM based authentication remains to be seen.

Interesting features to add could be:

  • Lock the token to IMSI or IMEI (possible, according to [10])
  • Use the network to initiate authentication transactions (drawback: implies sending service SMS messages to the token, which may mean cooperation of a MNO or at least per-transaction costs)
  • Use the network as an OOB channel during an authentication session (e.g. to display transaction details, similar drawback as above)
  • Use the network to “blacklist” a token when a token is reported stolen
  • Combine SIM augmented solution with a handset resident application to provide a better user experience (may be dependent on operating system and handset to provide installed apps with an API for communication with SIM)

The latter option is particularly attractive as a way to enhance the security of SURFnet’s tiqr solution (see [11]) and other mobile app solutions.

Since a one-size-fits-all solution to authentication does not exist, in the end SIM augmented solutions will likely find a market alongside authentication tokens with different form factors.

Mobile-centric identity in the IDentity.Next newsletter


Below a contribution I wrote for the IDentity.Next newsletter  (I’m on the expert panel) on mobile-centric identity, see also

Mobile phone – the remote control of our (digital) identity?


For most people the mobile (smart) phone is the most personal device they have. You carry it with you almost always, you rarely let others use it and you notice it is gone very quickly. Combine this with the smart phone becoming a mature and popular channel to online services, and you realize the importance of your mobile phone for your digital identity. The term user centric identity was (or still is) quite popular the last few years, going further I’m a strong believer in mobile centric identity: the mobile phone as the central component to control your digital identity.

I distinguish three ways in which this is happening:

1.     The mobile phone as authentication device– this is already happening and is progressing, especially one-time-passwords over SMS are pretty common. But also apps for Android or iPhone with one-time-password generators, or Mobile PKI which exploits the SIM card for more security.

2.     Authentication for the mobile channel– this is still a struggle, even more than identity on the ‘fixed’ internet. Typing passwords is a huge hassle on mobile phones, and providing these to random and barely trusted mobile apps is not a good idea (for example a third party mobile banking app). Common stronger authentication means like smartcards-with-readers or one-time-password tokens  are not really an option since no one wants to carry additional devices with them. Also identity federation standards like SAML WebSSO and OpenID are not really suitable for mobile phones. We’ve been using oAuth for mobile Apps, which may not be the final solution but is a step into the right direction if ‘medium’ security is good enough.

3.     Control your privacy on your mobile phone – I, and many with me, believe that sharing personal data can make our lives easier, but that the user should be in control of this. A single point of control for this is the way to go, for example determine in a central place who should get access to my new home address, and my location updates. This starts at basic consent functionality when using external identities (e.g., OpenID), but goes all the way to Personal Data Ecosystem, Vendor Relationship Management and User Managed Access ambitions. The mobile could be the trusted device to control this. This is far from reality nowadays.

A major risk for the success and speed in which mobile centric identity will come to be is if we are successful in keeping the mobile phone secure enough for this. This has not been a major issue yet, but for sure requires attention (for example, ENISA report or KuppingerCole Top Trends 2011). Solutions that are part of the operating system and/or exploit trusted hardware like the SIM card may prove most successful.

Related to identity is always payment, and although slower than expected the signs are good that NFC technology (for mobile payments) will get a significant penetration to mobile phones the coming years. Also, at least in the Netherlands, banks and mobile operators have joint forces to make mobile payment possible. Your mobile phone may very well replace both the coins and the bank/smartcards that are now in your wallet. It will be interesting to see how, how fast and who will profit from this!

Maarten Wegdam (principal researcher at Novay – member of IDentity.Next expert panel)

SMS one-time-password no longer enough for national electronic health record


Example personalized conversion table

Although not a very pressing matter because the introduction Dutch national electronic health record is delayed due to privacy concern in the Dutch Senate (Eerste Kamer), there is now a change of mind with respect to how citizens have to authenticate themselves to access their own health record. The responsible ministry VWS asked PWC and Radboud University to re-assess if their assessment from December 2008 on using SMS one-time-password is still valid.  In Decmeber 2008 they assessed a two-factor user/password is secure enough (although with an added face-2-face registration step compared to the ‘normal’ DigiD level 2). The reason why VWS asked for this only a year and halve after the previous assessment is that a practical attack on the encryption algorithm A5/1 used in GSM seems increasingly likely. I guess most if not all experts agree that within a couple of years GSM SMSes are simply not a valid authentication means for any service that requires high security, see e.g.’s opinion. Certainly not as a single factor, but also not when combined a not-so-secure second factor like username/password.

To increase safety PWC/RU propose a third factor. This is a personalized conversion table that is, typically, send by snail mail to the user’s home address. Users have to use this conversion table to char-by-char replace the one-time-password with another character (see above for an example picture of conversion table). This may be an easy solution/work-around to implement, but I think is a usability nightmare since it basically means that users are required to become crypto algorithms! Without some user research showing otherwise I wouldn’t dare to recommend it. My colleague Martijn Oostdijk proposed today in a blog post to implement the conversion table as a SIM application on a mobile phone, that may help here. This of course requires the corporation of all three mobile operators in the Netherlands, this may not be trivial, quick or cheap to get.

The reason that this is all so complicated is because the Dutch citizen-2-government authentication solution DigiD is not really that secure. This may not have been needed so far, but with increasing likelihood of practical attacks of the SMS one-time-password, and government services needing higher levels of assurance, the current DigiD level 2 is simply not “good enough security” anymore. A likely candidate to make DigiD more secure is a smart card solution called eNIK, which adds a electronic authentication function to the new Dutch ID card. Plans for this exist already for quite some years, but hopefully they will be able to speed up this process, or find another solution in the near term. Since actual attacks to read SMSes are not here yet, I think we should use this time to come up with a better solution to make DigiD safer than a work-around which requires users to become crypto algorithms!!

Mobile PKI and mobile centric identity


Together with my colleague Martijn Oostdijk (see also his post) we did a project on Mobile PKI technology. We did a technology assessment, focusing on security and also usability, and consulted our client SURFNet on its application for higher education and research.

It proved to be a very interesting project, not only because of the interesting and promising technology, but also because we are advocating what we call mobile centric identity, and Mobile PKI is a good example of “use your mobile phone as an authentication device”. We concluded that Mobile PKI is both a secure and usable technology, and that the main issue is the business model (since the SIM is owned by the mobile operator).

The report that came out of the project is publicly available: in Dutch and in English. Among others, SURFnet employees Roland Rijswijk and Joost van Dijk also provided input and feedback on this report. Below I’ve copied the management summary.

A GSM/UMTS telephone has a SIM card. This is a standardised smartcard that is issued to the user by the telecom operator and is primarily used to authenticate the user on the mobile network. However, the SIM card has more potential uses. For instance, it allows for secure storage of digital keys that can be used for online authentication and digital signatures. This is referred to as Wireless PKI and Mobile PKI.
This report is an assessment of Mobile PKI technology and its potential application for authentication in education. This assessment focuses on its security and its application within the educational domain, with a specific emphasis on applications for SURFfederatie.
Mobile PKI employs encrypted SMS text messages that are used to represent authentication or a digital signature. The user has to express consent by entering a PIN code that secures the private key and which typically needs to be entered for each transaction separately. The relevant standards for this are well established and are supported on all mobile phones. This has advantages compared to other secure means of authentication. For instance, no additional authentication device is required, which also means that no software needs to be installed by the user on either the phone or on other client devices such as a PC. Neither is there a need to manually enter codes, as in the case of one-time passwords via SMS text messages. This improves user-friendliness. Malware such as viruses and key loggers that may have been installed on a PC cannot interfere with Mobile PKI.
This report considers the issue whether Mobile PKI is a secure means of authentication. The analysis identifies a “man in the middle” channel. However, the authors of this report deem Mobile PKI to be more than sufficiently secure compared to other means of authentication and considering the kind of applications in (higher) education.
In our view the most important issues regarding Mobile PKI technology are not related to security or technology but have to do with the costs and the business model. In the Netherlands, Mobile PKI technology has only been deployed for limited pilots and it is therefore difficult to estimate the costs. These could turn out to be too high for many applications in the educational domain if there are no other large-scale deployments of Mobile PKI. A related aspect is the business model. Use of this technology requires the cooperation of the mobile operator, who is the owner of the SIM card. This means that the cooperation of all mobile operators is required for a large-scale deployment.
The final conclusion of this report is that Mobile PKI provides a secure means of authentication that in time will find wide application within the educational domain in the Netherlands. For the near future Mobile PKI will only be employed for services that require a high standard of security and that are used by a limited group of employees due to a) the expected costs, b) insufficient insight into the business model, and c) limited support from the mobile operators. It seems too early for a deployment for students or for general authentication for SURFfederatie or any other large-scale application for SURFnet, Kennisnet or other service. In the meantime it may be useful to consider one-time passwords via SMS text messages as step-up authentication or for password reset because this is cheaper and prepares users for Mobile PKI.

Presentations on Id Fed, user centric and mobile centric identity


I gave two presentation recently that I’ll share in this post. They were for quite different audiences, and in different countries, but both in the area of identity federation, user centric identity and mobile centric identity.

The first presentation was at the Dutch Identity 2009 event, which was co-located with ISSE 2009 this year. This took place in Schevingen (The Hague), on 6-7 October 2009.  I presented my views on trend in identity federation, and user centric identity. Among others, I argued that SAML is just as user centric than OpenID, or at least, can and should be…

Highlights on Identity/ISSE 2009 for me were the presentations by Don Schmidt (Microsoft), who talked about claim-based identity, and a presentation on the Norwegian BankID, which discussed the status of the Norwegian collaboration between banks to provide identity services to public and private sector.

The second presentation was at the National eID & ePassport conference, which is taking place as I type this (22-23 October 2009), in Lisbon. It was organized by among others Multicert, who invited me to talk about and discuss mobile centric identity. It was an audience not very familiar with user centric identity, so I first introduced this. I then argued that this implies mobile centric identity, and that using the mobile phone is only the first step towards mobile centric identity.