Identity is king

Many large distributed systems have on success criterion in common – identity (management). This is true for social networks (we all love to be part of), e-commerce platforms, systems operated in the clouds as well as for networks in the realm of automated demand/supply operation (aka Smart Grids). The requirements are not new at all: the identity of a large number of participants must be handled in a way that peers can trust each other based on one or more identity providers. Identity is needed for authentication in order to enforce access control to a resource (a website with profile information, a virtual shopping cart, a database table, a data point, whatever). It’s about the identity of the subject (the source) which has initiated the request to get access to a resource. Before the access rules can be applied (authorization), this authentication must be handled in a trustworthy way. This is complex to achieve, especially in case of multiple domains that operate their own realm of trust. This kind of trust is a precious thing that needs to be protected and maintained. Beside all theory and technical details, it (the precious thing of digital identities in an existing community) is an important asset. A social network identity could be used to get access granted to other resources like a virtual shopping mall or a booking engine for last minute flights. More scenarios are obvious ….

Folks, it's the spring!

In times of the 'GREEN IT', it's absolutely necessary to post such a picture on a software blog! ;-)

Software Architecture and balancing stakeholder needs

I recognized recently that I blog a lot about computer security (because of several reasons). This is definitely not a boring topic. On the contrary, it’s complex, fascinating and a fast moving target. You need a decent understanding in computer science to keep up with all the things going on out there. On the other hand, the area of system security (comprising computer and network security) is full of misconceptions. Too many people still believe that a firewall is the silver bullet to keep out attackers, worms and other malware. I don’t comment on that anymore. But this never ending discussion leads me to one of my core competences – software architecture and all the team, communication and development related aspects. A software architect needs to understand stakeholder needs. Typical stakeholders are end user, developer, test stuff, marketing folks, project manager, just to name a couple of them. But understanding and documenting is not enough. A stable and successful architecture balances stakeholder needs and reflects this in all their lifecycle stages, from requirement management until testing, delivery and maintenance. I know this happens just in theory, in an ideal world somewhere in a software glasshouse. But we should strive to come closer. Achieving tradeoffs is an important success criterion in the process of creating a stable and lasting architecture. These tradeoffs should be the result of negotiations with the ultimate goal to come to a win-win situation for all participants (àstakeholders). From the technical perspective, most of the tradeoffs must be achieved between functional and non-functional requirements (aka quality attributes). From this we see that there is s strong link to security as an essential quality attribute in a connected world of ubiquitous computing and routed protocols. Many design decisions in the scope of security architecture are in marked contrast to the ideas of usability folks and the needs of project management. But these contradictions must be addressed and resolved, which might be a tough job. Anyhow, for the sake of a successful product achieving broad market acceptance, failing in balancing stakeholders needs is not option.

Computer Security in the scope Web 2.0

The current issue of ACM Queue puts Web Security in focus. One article is titled Cybercrime 2.0: When the Cloud Turns Dark. In essence, it is really hard to disagree. I could just add a couple of web attack scenarios based on update services or instant messaging. A lack of security in the design of web applications and the underlying infrastructure is the root cause, as stated in the conclusion of the article. But it is really hard to see some kind of remedy in the near future. On the contrary, new solutions like offline web-applications, cloud computing and the so called Web-OS are all based on vulnerable technologies but connect a large number of users and machines. This will increase the attack surface because each single hole in the system might give an attacker access to a large network of assets and services. Some people call these new applications and architecture already Web 3.0. Unfortunately, nothing has changed in terms of security.

Waiting for my Netbook

There are rumors about a netbook made by Apple. Beside many other sources, Gizmodo came up with a couple of information and pics (touchscreen, …). The assumption that this gadget will be available before Christmas sounds logically. It makes my life easier picking up the right present for myself … :-)

Silverlight 3 at Mix09 / Las Vegas

The most important fact is that Silverlight 3 Applications (basically a subset of WPF) can be deployed and executed outside the browser in a sandbox. Beside this deployment scenario, advanced video features (H.264) and an updated version of Blend are the most remarkable renewals for the smart client ecosystem.

More testing tools for parallelization

Intel® offers a so called “Application Concurrency Audit Tool” for free. The Intel® Concurrency Checker 2.1 is available for Windows and LINUX and can be downloaded from their software network. I started to play around a little bit with the tool. It provides a decent overview on CPU utilization, elapsed time, parallel time, utilization regarding threads, and levels of concurrency. It allows to attach running application executables as well as to test java apps.

What's on my reading list?

Four books, basically:

• the Long Tail by Chris Anderson
  ... recommende for all people interested in the new economy and e-commerce
• Outliers by Malcolm Gladwell
  ... its about genius
• Das Scheekind by Nicholas Vanier
  ... a musher travels BC and Alaska with his wife and a baby
• Mechanics of User Identification and Authentication, by Dobromir Todorov
  .. it's for geeks

Offline-Web Applications & Security

We can read a lot about Computing in the Clouds these days, even in ordinary newspapers. It’s a big business with SOME open questions. I started to compile a couple of thoughts in Web Browser, Web-OS and the Era of Cloud. Beside the real differences to Client-Server Computing (“Dude, sometimes I can spot them, and sometimes not!”), I do have my concerns pertaining to security. Take the so called Offline-Web Applications (sometimes called Web 3.0) for example. Beside the fact that this word is a contradiction in itself, the vulnerabilities are an existing problem. Running web servers everywhere increases the attack surface. The HTTP-servers on the client machines are needed to keep the applications (that are web applications) running in case of a network blackout. In addition, to maintain state is another must to allow a kinda real application feeling. Maintaining state in the scope of web application based on HTTP with all consequences has been a security problem from the beginning. Nowadays, state is maintained by using cookies and other remnants initiated and used by browsers and plug-ins. Talking about Offline-Web Applications, small databases on client-side are in use. But this list is not complete yet. HTML 5 specifies a Structured Client Side Storage which includes database storage (local and relational). Some Web-browser vendors are planning to support to a certain degree (session, local, database). This will change attack scenarios as well as attack surface. Combined with excessive scripting, but this is another story …

Dresden’s castle got a (new) roof

webduke pics 2009

more pics on:
http://www.panoramio.com/user/1514395

(These Days) Development Skills

I do remember times very well when software development was envisioned as a process of combining components (either ActiveX or some kind of Beans), and smart people started to perceive software as a kinda utility (like water, electricity or network access). I did not comment on this. Talking about the technical aspects, not much has changed. Writing (beautiful) code is still a creative and a heuristic process. And, beside patterns and practice, it needs strong skills and a lot of experience. Again, there is nothing new about this (since 19** ?). Just two examples from today’s problem spaces: parallelization and distributed apps on a large scale. To cope with today’s hardware platforms (multi-core) needs a lot of knowledge and diligence in developing applications running on them. There is no magic tool, workbench, compiler, etc. to solve such problems implicitly, not yet. You need a decent understanding of processors, cashing, threads and shared memory. Sure, testing this stuff comes with another steep learning curve. Secondly, largely distributed systems (take upcoming clouds as an example) do need a different approach pertaining to availability and consistency (see my posts on BASE, CAP, etc.). It’s up to the development team to hide the trade-off between data consistency, system availability, and tolerance to network partitions. This is not a piece of cake. It needs new approaches and thinking models, pretty similar as when we moved from the client server-paradigm to more or less simple distributed- application-patterns. In essence, the heuristic part of software development is alive and kicking.

Security in Cloud Computing (Distributed Systems)

Security is one of the most important requirements to make a software system running in the cloud acceptable for the intended user community. This is especially true in times like this where people’s privacy is under attack on a daily basis. Just follow the news in Germany. It’s a big concern and not far fetched, not at all.
Computer security got a couple of basic pillars; Identity Management is one of them. In the new realm of cloud computing, this comes along with authentication and authorization in distributed systems. SAML (the SAML 2.0 protocol) and OpenID are more or less standards to support the implementation, also in terms of interoperability. Big vendor’s cloud architectures (just see the Geneva project as an example) do support these standards. This is not just a good approach in terms of interoperability; it also leads to a better understanding and visibility regarding the underlying implementation and infrastructure which probably leads to more trust and better acceptance.

New Pics on Panoramio

Friends, a added new pics to my Panoramio Account. Just check on: http://www.panoramio.com/user/1514395

Beautiful Dresden in wintertime

My technical wish-list for 2009

Talking about the New Year - What do I expect from the technical perspective? Here comes my wish-list which is a blend of my expectations and the trends I see in general for 2009.

• A better support for effective parallel programming, also with a more implicit approach
• New solutions to interact with smart devices (cell phones) to overcome tiny keyboards and cumbersome handling
• A synthesis of a Handheld-GPS and a simple mobile phone to reduce the number of devices in the outdoors (let’s call it a rugged GPS-Phone)
• Cool applications (and gadgets) making use of the so-called “cloud computing”
• GPS and RFID in much more tools and gadgets (cameras, mobile phones, bikes…) with the option to switch it off anytime
• Location Based Services (ez to use, respecting privacy, useful) with real benefits for the user
• NetBooks for all known OS platforms
• Home automation for mainstream households; many use cases are conceivable and could help saving energy, this would give the buzzword “Green IT” a very new meaning
• More awareness of security and privacy issues in a connected world which leads to new options to protect digital information, assets, and people’s privacy
• E-books based on gadgets and applications that create a new reading experience; don’t get me wrong, I will always stick to real books made of paper but I see E-books as a interesting alternative beyond the advantage to carry a lot of books wedged in a handy device when travelling
• A new album from my favorite band TOOL
• Anything to add? Feel free to comment.

Merry Christmas and Happy New Year!

I still hope for a White Christmas and perfect ski conditions.
Let There Be Peace on Earth!

ACID, BASE, CAP and the Clouds

This is not about chemistry, medication or transcendent music. But it is a fussy topic. I assume the ACID (Atomicity Consistency Isolation Durability) paradigm is well known and understood from working with databases or in the scope of transactional logic. But this is about to change in large distributed applications running in the clouds (of whatever flavor) with distributed data repositories (e.g.: partitioned databases on distributed nodes). Running in clouds implies the utilization of web services predominantly. This environment leads to the CAP theorem which is about Consistency, Availability and Partition Tolerance with the restriction that only two goals (of CAP) can be achieved in a real world implementation. So it is up to application development to decide between availability and consistency and to conceal this conflict by different means, for instance by using a smart user interface logic and design as well as sophisticated update and messaging strategies in order to achieve consistency in the second step. - I apologize for oversimplifying this whole topic for the sake of a concise post. – Anyhow, this is already in place in large online-stores. To bring the third acronym into the game, an approach to make this happen is called BASE. It stands for Basically Available, Soft state, Eventually consistent). An architecture based on decoupled subsystems is an important prerequisite to achieve this.
There is nothing new about these acronyms and the paradigm change. Great articles can be found on the web (for instance Werner Vogel’s “Eventually consistent”) or other stuff especially available at ACM QUEUE. I just wanted to emphasize the need to check on this from the architectural perspective in order to answer the question: Is this application the appropriate choice to be deployed in the clouds or not? Or say it the other way around: Is BASE good enough for you? Or, is ACID essential for your system and the underlying requirements that are basically quality attributes? For many systems in the industrial domain (where data integrity and consistency is king) the answer might be not (or probably not yet). To answer these question correctly in order to adhere to such paradigms (or not), is essential because the clouds are already on the horizon.

More Parallelism Support in upcoming IDE version

The October issue of the MSDN magazine contains an article on the improved support for parallelism in the next version of Visual Studio [v. 10] as well as in .NET 4.0. Stuff from the Parallel Extensions (TPL, PLINQ) to the .Net 3.5 Framework (available as Community Technology Preview) went in as well as new features to support parallelism in native code. In addition, testing tools to cover parallelism in code are in the pipeline too. Most of these new features were presented at this year’s PDC in Los Angeles (slides are available for download). This is definitely a step in the right direction but a long road to go until writing parallel code is daily business for mainstream programmers. I got still concerns if existing programming languages, libraries, frameworks and compilers can deliver the final answer to cope with the complexity of expressing explicit parallelism.

New Music on my turntable

Talking about the stock market, the October was a nightmare; everything went south. Fortunately, there is still Rock’n’Roll (“There is noting conceptual better than Rock’n’Roll!”, you remember John Lennon saying this in an Rolling Stone interview? It is so true, so true!). Well, the October was not so bad in terms of new releases. Here are my new acquisitions:

• Metallica - "Death Magnetic" [****]
• Oasis - "Dig Out Your Soul" [***]
• ACDC – "Black Ice" [*****]
  Please note, ACDC gets five stars [*****] by default.

Mauerfall und Schwarze Schwäne

Heute vor 19 Jahren ist die Mauer, ein Symbol von Unfreiheit und Unterdrückung, gefallen. Momentan lese ich gerade „The Black Swan“ von Nassim Nicholas Taleb. Wie passt das zusammen? Für mich ist der Mauerfall ein typischer Schwarzer Schwan, der alle Eigenschaften erfüllt, die Taleb in seinem Buch beschreibt: selten (rare), mit extremen Auswirkungen (extreme impact) und rückblickend vorhersehbar (retrospective predictable), ein so genannter Outliner. Natürlich ist das eine theoretische, fast schon philosophische Sichtweise, die die emotionalen Gesichtspunkte eines solchen Ereignisses (das extreme Leid vorher und die überschwängliche Freude beim Fall der Mauer) nur ungenügend berücksichtigt. Sie birgt aber auch die Hoffnung, das es in Zukunft ähnliche Schwarze Schwäne geben kann, die unterdrückten Menschen in Not endlich Freiheit und Demokratie bringen werden.