Stop in Bratislava

My Eastern European tour this summer was firstly enriched by our stop in Slovakia’s capital – Bratislava. The weather and the brilliant blue sky served us well as our group set off to explore the many grandiose buildings and castles. There were no signs of the city’s Communist period – the archiecture and town squares were enlivened and built in a renaissance and baroque style. Around every corner it was easy to come across one of the city’s funny statues such as Cumil. We’re not quite sure what he is up to, cleaning the sewer or just having a rest after a hard day’s work.

Cumil. Man at Work

The soldier resting on the bench reminds visitors of Napoleon’s first visit to Bratislava in 1809.

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Napoleon’s Army Soldier

A charismatic figure known as Schoner Naci wearing a top hat is ready to greet you in the beautiful city.

Schoner Naci

The highlight of the day was definitely a tour up the Bratislava Castle built in the 9th century. From the top there are great views of the city and parts of neighbouring countries such as Hungary and Austria. Known for its history with the Romans and the Celts, the castle stands as a major tourist attraction.

Bratislava Castle

Thank you Bratislava ! It was lovely !! Dovidenia

Sybil Attacks: Nodes and Attack Edges

attack edges

The system is constructed with the formalization of honest and malicious users, which are specifically exemplified in Sybil Guard as nodes. The way to recognize potential attackers is by identifying how many identities one user occupies. For example, honest users have only one identity while the attacker has many identities, which the protocol detects.

As Yu and his contributing experts assert, ‘all honest nodes and sybil nodes in the system form a social network’ (Yu et al., 2008), which is precisely demonstrated in the given figure.

Subsequently, if two users are linked without corruptive intent and form an honest relationship, we call that connection an edge. In contrast, any honest user or node that connects with an attacker forms an attack edge. In the process of regulating potential attackers, this graph proves to be effective. Not only does it limit ‘the number of attack edges’ (Yu et al., 2008), it also concludes with the proposition that reliable users don’t need to form any bonds because they already have established friends, whereas, the intention of sybil attackers is to add friends which inevitably dispatches several attack edges. This model allows Sybil Guard to defend social networks against sybil intruders by obstructing and restricting the number of ‘false’ relationships one attacker creates.

 

References:

Yu, H., Kaminsky, M., Gibbons, P. B., & Flaxman A.D. (2008). SybilGuard: Defending against sybil attacks via social networks. IEEE/ACM Transactions on Networking, 16(3), 576-589.

 

 

Beaufort Street Festival

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More than 100 000 visitors took to the annual Beaufort Street Festival to celebrate one of the most iconic streets in WA. A massive crowd gathered to enjoy the fun: food stalls, art installations, fashion and live music provided a great entertainment for all ages.

Definitely a must-see street to enjoy, shop and have fun with family and friends all day long!

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Sybil Attacks: Sybil Guard or puzzles?

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Sybil Guard is a decentralized system that ‘limits the corruptive influence of Sybil attacks’ (Yu et al., 2008) and determines potential attackers by using a graph system. This innovative system will ensure the verification of Sybil attacks by differentiating links in the graph, between Sybil nodes and human established connections known as honest nodes. In the world of social networking, Sybil Guard works efficiently. Subsequently, this mechanism is comprised with characteristics that will maintain security and trust in online social networking sites by identifying honest and malicious activity among users and networks. These characteristics will include the dissemination of attack edges that are vital to interpret malicious behaviour.

Another algorithm that is proposed is the conception of installing ‘computational puzzles to be solved prior to granting new identities’ (Cordeiro, Santos, Mauch, Barcelos, & Gaspary, 2012). Even though this approach will minimize attackers and the stealth of identities, there is a crucial disadvantage to this protocol. By assigning these puzzles that are targeted to confront sybil activity, honest users are coupled with this intractable task. In defense to this slight flaw, experts recommend higher, more complex puzzles to attackers while genuine users will be conformed to easier puzzles. As a result, by establishing these puzzles, the number of sybil attacks is brought to a minimum without ‘compromising the intrinsic characteristics of P2P networks’ (Cordeiro et al., 2012). In contrast to previous undertaken experiments, this mechanism will possess an ‘adaptive’ puzzle mechanism for identity administration and legitimization. Part 3: Nodes & Attack Edges.

References:

Yu, H., Kaminsky, M., Gibbons, P. B., & Flaxman A.D. (2008). SybilGuard: Defending against sybil attacks via social networks. IEEE/ACM Transactions on Networking, 16(3), 576-589.

Cordeiro, W. L. D., Santos, F. R., Mauch, G. H., Barcelos, M. P., & Gaspary, L. P. (2012). Identity management based on adaptive puzzles to protect P2P systems. Computer Networks, 56(11), 2569-2589.

Sybil Attacks

Social networks take over the world

Recent statistics reveal that over ‘1 billion users are connected through online social networks’ (Chbeir, 2013, n. p.), which is indeed, a staggering figure that calls for our attention. Social networks are exceeding our expectations in the ways we connect, communicate and understand the computerized world of today. However, as the numbers get higher, so should our awareness and understanding increase for the vulnerabilities and threats such networks pose given our excessive interchange of data and identities.

Sybil Attacks                ‘A hidden connection is stronger than an obvious one.’ – Heraclitus

All distributional systems, including social networks, are sensitive to Sybil attacks, which are otherwise known as clone attacks in computer science. The most evident intrusion of counterfeit profiles is seen in social networking sites, where users unintentionally consign their data and ‘identities’ to unknown systems or to possible ‘attackers’ in this case. A Sybil attack is the corruptive act of stealing and manipulating identities in the spheres of networking systems. The attack is established when a ‘malicious user takes on multiple identities and pretends to be multiple, distinct nodes in the system’ (Yu, Kaminsky, Gibbons, & Flaxman, 2008).

Source: Social Media apps [Digital Image], 2013.

Source: Social Media apps [Digital Image], 2013.

There are two main types of systems that are targeted: systems with a trusted authority, which are more reliable, and decentralized systems that are more vulnerable to Sybil attacks. The attackers are less likely to enter trusted systems given the requirement of various security codes and in advance payments. However, there is a certain drawback with the user’s probable refusal to provide the system with confidential and private information. On the other hand, experts are more focused on identifying specific approaches and strategies to accommodate users and prevent Sybil attacks in decentralized systems. As a result, experts and researchers have proposed the inauguration of IP addresses and their close link to an identity. Nonetheless, this strategy proves to be short-term and an ineffective solution given that ‘malicious users can easily harvest IP addresses’ (Yu et al., 2008). As an alternative to these two major systems, experts introduce Sybil Guard, a new defence scheme. In addition, another solution is seen in the problem-solving stratagem to protect identities and systems which will nevertheless prove challenging, both to users and experts alike. Part 2: Sybil Guard or Puzzles?

References:

Yu, H., Kaminsky, M., Gibbons, P. B., & Flaxman A.D. (2008). SybilGuard: Defending against sybil attacks via social networks. IEEE/ACM Transactions on Networking, 16(3), 576-589.

Chbeir, R. (2013). Security and privacy preserving in social networks. Dordrecht, Netherlands: Springer.

Rome to Remember

It was my first trip to Italy, a surprise holiday for my mum and for sure the first city to visit that came to mind was: Rome! Known as the Eternal City, Rome is a mesmerizing city where every step led me to amazing views that would make me halt, stop and take a photo. My hotel was situated very close to the Colosseum itself, a mere 5 minute walk. I remember the first time I caught sight of the Colosseum, a medieval architectural masterpiece of the capital . It simply took my breath away. I noticed how grand and majestic it stood compared to my miniscule self in a picture.

Unfortunately it was a short 3-day trip, therefore I was limited in my desire to go everywhere and explore everything. I did however manage to visit the famous landmarks such as the Pantheon, the Roman Forum, the Arch of Constantine, the monument to Vittorio Emanuele II, and the tall column of Marcus Aurelius. I was really excited for the Trevi Fountain yet was shortly disappointed to see that it was under construction. Just around the corner was my ascend up the Spanish Steps at the Piazza di Spagna. Breathtaking. I have to mention the beautiful boutiques and parks, the tasty Italian cuisine from their traditional trademark pizzas (with mozzarella and tomato sauce), spaghetti and the espresso of course! I even watched a World Cup match on a huge screen in the main street of Rome, cheering along with many other tourists with a beautiful and starry sky above us. Witnessed a couple of weddings take place on the streets. Summer was in full swing.

The bustling city of Rome with its ancient and rich history is a city I will love to visit again.

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Beautiful streets of Rome

Overlooking the ancient city of Rome

Overlooking the ancient city of Rome

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At the monument of Vittorio Emanuele II

The Spanish Steps - Piazza di Spagna

The Spanish Steps – Piazza di Spagna

View of Rome from the Capitoline steps

View of Rome from the Capitoline steps

Artwork and book displays

Artwork and book displays

Believe it or not!

Believe it or not!

The Colosseum at night

The Colosseum at night

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From Line to Life

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The object of art is not to reproduce reality, but to create a reality of the same intensity.” – Alberto Giacometti

Drawing and painting: Two things I enjoy. I came across this drawing of footballer Cristiano Ronaldo that I finished not that long ago, which reminded me how much I love art. Whether they be in graphite black and white pencil or water color, I try to give every piece of my work life. No matter the frustration I might go through, the journey is what counts. With everything we do in life, we learn something new that inspires us to always go one step further – every time. Same goes with art. Sometimes what we don’t expect to turn up right, gets a thumbs up!

I have taken several visual arts classes from contemporary art to a interesting drawing class that has helped me work with various mediums in different ways. In the meantime, my passion for languages, especially the French language and its culture is what I decided to continue on with at university. However, I believe art will always be a part of me and I will continue to draw, create, smudge and paint to my hearts’ content no matter what!