jump to navigation

Finally the thesis November 27, 2009

Posted by tcarlyle in identity management, Me, Sensors, SIM Cards, Thesis, trust, Uncategorized.
Tags: , , ,

After almost six months that I have delivered my thesis, I’m finally posting it here. It turned up to be a very extensive document (about 150 pages), but mainly because we first wanted to assess the capabilities of SIM cards, identities and finally trust frameworks. And as I was working together with the SIM Research Team at Telenor and I do have some experience with SIM from when I worked in Gemalto, we spent several pages on reviewing the SIM capabilities and trying to figure it out the future SIM.  We also touched an aspect that may start to become more present in the SIM cards which is the ability to sense context.

Other pages were spent in getting into the identity management world and this was one part of the thesis which in fact I wished I had more time to go through. I got very interested in going deeper in the field after finally understanding the identity frameworks such as Higgins, Cardspace and specially on the concepts in which they are based. At last we studied a bit about trust models and this was one of the most difficult parts of the thesis as none of us had much an idea of trust modeling and it is a topic that can get very complex if studied deeply.

After this long background, we finally chosen a new application that could be hosted in the state-of-art (or future) SIM cards, take advantage of the fact that the SIM represent one or more identities and that can be used to build trust. That application was what I have proposed in my paper mentioned in the previous post.

The idea is to use the future sim cards to sense each other (either through NFC,  location information and server interaction, wlan, etc), to sense the environment and based on that, attribute a situational trust value for that meeting between the 2 sim holders.  Then with a bunch of those situational trust value, you can infer the user relation. The more context information, the more you can infer.

Based on that idea, we made a small prototype using SunSpots representing those advanced SIM cards and with a simple trust inference model and a test scenario.  It  may sound a simple test and in fact it was, as the thesis focused a bit on bringing a new idea (which is extensively described) and the state-of-art research, having the prototype as a small proof-of-concept.

When I was reviweing the thesis for the paper presentation, I read in Bruce Schneier‘s blog about a paper from some researchers from the Santa Fe institute that used location information and phone calls information to infer the friendship closeness between the people involved in the experiment. The result was that they could predict the level of friendship with 95% accuracy! This pretty much confirm my thesis result =)


First day of Nordsec 09 October 15, 2009

Posted by tcarlyle in Biometrics, identity management, SIM Cards, trust, Uncategorized.
Tags: , , , , , , ,
add a comment

I’m bloging directly from the Nordsec 09 conference here in Oslo. So far it has passed one day and a half and the programme has been quite interesting. There has been a more strong focus on identity and privacy, and, moreover more “high-level” presentations than the conference last year. As the conference programme has been quite extensive I must assume not having payed full attention to all presentations and specially the ones that didn’t have slides as supporting material. I’ll cover in this post just a bit of my impressions around the first day.

The first day was mainly about identity and privacy.  We started with a great presentation from Drummond Reed from the Information Card Foundation. He end up spending some of time explaining IdM as the concept was not familiar for the whole public, then he talked a bit on the challenges to using the open ID standards by the governments, in special in the USA. He also mentioned the issue of having a branding competition on the websites towards the several OpenID providers. It was pretty interesting to see that the US government is going for an exisiting open IdM standard and also to know that apparently a lot of the companies that seemed to be competing for IdM ownership seem to be cooperating more. At least, as far as I got there are several new players joining the OpenID (although it is not clear if they are just offering authentication tokens or if they are also accepting other OpenID tokens) and the Information card has become a common format shared between Cardspace, Higgins and other selectors.

There was a presentation about Identity Theft from the Ministry of Justice and the Police of Norway. The presentation was mainly on how biometrics could help to prevent Identity Theft. As the usage of biometrics in his speech was not characterized if it was for identification or authentication as I mentioned in a post in the blog, it generated a lot of questions around the dangers of impersonating someone using a copy of the biometric template which could be gathered through a fingerprint left in a glass for example. This generated some discussion around storage of the biometric template and issues around biometrics in unsupervisioned scenario which the speech could have maybe addressed and made itself even more interesting.

Later we had a presentation of Tor-Hjalmar Johannessen from Telenor presenting arguments towards having an e-ID centric model on the SIM with very logical arguments. He bases it in the massive presence of sim cards, its security, the fact that they already represent an excellent working case of IdM (roaming is single-sign-on), new enhacements to the SIM as a hardware and software platform and others. I had already seen other of this presentations on the topic and I’ve read a few of his papers for my Master Thesis. Therefore, it was not something completly new for me, but it already introduced the audience in the topic which will be good for my presentation on Friday =)

Other 2 presentation that specially called my attention were the one about “Privacy risks in Web 2.0” from Roar Thon from the Norwegian National Security Authority and the one about the future e-voting system in Norway. The first one was a bit more on the need of creating awareness around how much private information we are publishing and distributing. It was interesting to see tha the  Norwegian National Security Authority is interested in that and also on some numbers presented. In fact the presentation opened the point of the lack of attribution of social networks relations which is something Ill discuss in my presentation.

I think I’ve never stopped to think so much about the complexities around e-voting and the presentation from Christian Bull gave a great overview. There are issues on the fact that you are not over a supervisioned environment and this could lead to vote selling or coertion, or on making sure that every vote is counted but it is not possible to trace who voted in who, and there it goes. He presented a few neat features to counter some difficulties of the e-voting and the system sounds very promissing. It was also nice to see that they plan to make it open source so the system security can be assessed and they will submit it to common criteria evaluation (or a similar one, I dont quite remember).

I’m not sure if the presentations are going to be published in the conference website, but in case it will I write it here.

Trust March 24, 2009

Posted by tcarlyle in identity management, reputation systems, SIM Cards, trust.
Tags: , , , , ,
add a comment

“Trust – Trust is the characteristic that one entity is willing to rely upon a second entity to execute a set of actions and/or to make set of assertions about a set of subjects and/or scopes.” [from the WS-Trust spec ]

This means that one entity will claim some information about a subject to another that will rely on it. This is pretty much the same trust concept in the Identity Management models described in Cardspace (now codename Geneva), Higgins,  and other centralized approaches (that are actually based on the WS-Trust and WS-Security).

An user register himself (establish a relationship) with an IdP (Idenity Provider). Due to this relationship, the IdP is able to prove and manage user claims. This relationship between the user and the IdP, depending on the claims involved, should be based on SLA and the IdP may have to acquire data from the user (through the registration for example) by a reliable process (by checking the user national ID to be sure that he is an adult and etc).

The mentioned example is what is sometimes described in the literature as policy-based trust. It relies on the security behind the agreements of the Identity authorities which are enforced by certifications, auditions and SLAs. The trust result is a binary trust or not-trust to the claim.

However, trust can also be extended to reputation systems, where entities have their reputation rated by other users, that do not have a relationship build through SLA with them. This is of great usage in scenarios where it is important to generate trust over claims that are somehow subjective or context-dependent (such as: “is this an interesting article?” – that depends for whom, “is the staff of that restaurant friendly?” – that relies on a personal opinion) or when an IdP would not have enough mechanisms or would not be feasible to be responsible for the claims (such as in systems as on-line auctions).

In those cases, every individual taking part on the system and being able to create or support a claim is somehow an IdP. This mechanism, in general rely on a system or entity that offer an identity to the user so he can act as an “IdP” and which offers the IT infrastructure for those users to play that role. This entity or system can have a more neutral role as offering the IT infrastructure and the rules for the claim stating and support, or it may have a more active role such as mediating and filtering claims, giving special weights to some users claim based or requesting and validating information about the user that will act as an “IdP, in order to raise the trust over him.

By having each user as an IdP, they can establish digital relationship between themselves based on long-term relationship such as friendship or less established relations such as both were engaged in a operation that evolved trust (such as an online purchase) and everything was ok. Those long-term or short-term relations  could be exmplored to build a trust network, a web-of-trust, somehow similar to a federation (but more loose as it is not based in contracts).

This good article about reputation trust models describes, some researchdone towards the development of trust metrics that can predict the trustworthiness of a person or claim based on the relationship between the person or the claim owner and the trust network of the person who is accessing the claim. It actually points the concepts of Global Trust Metric which takes in consideration the opinion of the whole network in order to trace the trustworthiness of the claim and the Local Trust Network which restricts the trust building on taking into account just the feedback from users on the same trust network as the user who is checking the veracity of the claim.

This other arcticle, comments on the success of using reputation systems build over individual on-line feedbacks to provide reasonable trust in systems that seems really risky such as on-line auctions . Moreover, this kind of reputation based information is being more and more accredit and now represent a big weight in user’s decisions varying from choosing a music album to buy or which company to invest. Due to the fast dynamic of today’s world and the widespread of information, the lack of knowledge in some decisions is being compensated by information gathered through trust relationships.

I see a big trend in the usage of reputation systems for more and more cases. As an example wikipedia as a collaborative environment has a pretty similar trust base as a reputation system, and it is accepted by a great number of people as a very reliable information source (this post in fact shows that the wikipedia is as accurate as the Britannica encyclopedia). Based on that, I am currently reading about trust models in order to built seamless Local Trust Network based on the sim card pervasiveness, the new cool features showing up in the mobiles and the sim idenitities. In case you are looking for similar reading, please feel free to share and to ask me for arcticles I may have collected.