In the following short essay I will try to convince you that out of Titan, Enceladus, Mars, and Europa, Titan is the most likely planetary body to support life while Mars is the most unlikely. First let’s talk about what a planetary body requires in order to support life. In order to support life, a planetary body needs water or liquid, a protective sphere, and organic compounds. In addition to these vital entities we must also take in consideration the notion of origin of life and its maint... Read Full Story

Archaeologists in Russia have discovered an “extraordinary” group of Stone Age artworks which appear to have been carefully buried in pits and covered with mammoth bones, the researchers announced this week in a newly published paper. Archaeologists uncovered these Stone Age figures buried in pits southeast of Moscow. Archaeologists uncovered these Stone Age figures buried in pits southeast of Moscow. At least some of the 21,000-22,000-year-old objects appear to have been regarde... Read Full Story

Worms are replicating programs that propagate throughout the internet using emails, remote logins, etc. Worms also has phases much like a virus; dormant, propagation, trigger, and execute. Worms can hide themselves as system processes. One of the most famous worm was the Morris Worm that targeted Unix files over the internet. The number of hosts increases exponentially and the number increases in the middle of a worm’s life. The main objective to counter a worm is to identify it and stop it ... Read Full Story

Viruses are programs that infects applications. They modify the application and include a copy of the virus program in to it. Then they run in stealth while the host application is running. Viruses are also specific to operating systems and hardware. They can be designed to specifically take advantage of particular operating systems and hardware. A general virus goes through the following life-cycle: Dormant, propagation, triggering, and execution. The components of a virus are infection me... Read Full Story

A military style security system’s objective is to lock all information within the system. In this system, confidentiality is the most important aspect. Integrity and availability is not the priority. It is naturally a MAC policy where users are not trusted for their discretion. System pre-assigns users with their rights over classified files. In this model, we assume that the users cannot memorize crucial information and disclose it to an outsider, such actions would lead to severe penalties... Read Full Story

There are 3 types of policies, integrity, confidentiality, and availability policy. In confidentiality policy, the main concern is to not let the information be leaked to unauthorized subjects. In an integrity policy, information should not be modified by unauthorized subjects. Availability policy makes sure that the information is easily accessed by authorized subjects within an acceptable period of time. Applications in real world use a mix of these policies. Mostly, in military applicatio... Read Full Story

A basic definition of policy in system security is “what is allowed and what is not allowed“. And the respective mechanisms enforces policies. There are three goals of security: to prevent attackers from violating security policies, to detect attackers who are violating security policies, and to recover which stops the violation and repairs damage. The last one also includes the ability to function after being attacked. We assume that policies are unambiguously partition system states and t... Read Full Story

Unlike ACM, Access Control Lists stores each column with an object. Assume that black_socks is an object, and Hira is a subject, then an ACL rule would look something like this: black_socks: { (Hira, rwx) } Furthermore, we also have Capability Lists. Capability Lists looks just like ACL’s but they are written based on subjects. For example: Hira: { (black_socks, rwx) } An ACL answers “a given subject can access which objects?”. A CL answers “a given object can access which subject?”. There ... Read Full Story

We need some sort of way to know the current state of a system. We achieve that by having a “state” of a system which includes a collection of system settings and values. These can include entities like memory locations, register addresses, primary and secondary data storage devices, and other components crucial to the operating system. A subset of this state is a “protective state” of a system. This subset is relevant to the system’s security. So how do we mathematically represent the prote... Read Full Story

When you look at Jupiter, all you see is parallel constantly-varying bands and of course the mysterious red spot. The colors observed the bands varies from yellow, orange, brown, tan, red, and even shades of blue. The red spot is evidently a storm of twice the size of Earth that has been possibly active for centuries. Jupiter’s strong gravity is exhibited by the fact that even the gas like hydrogen can not escape its atmosphere. Not much have escaped from Jupiter’s atmosphere since its forma... Read Full Story