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Delay/Disruption Tolerant Network (DTN) : An Introduction

Coining a new terminology in the technical field requires a strong impulse. The concept of DTN arrived primarily to combat the disruption which occurs in conventional TCP/IP (Transmission Control Protocol). Our communication network has many mediums that a data packet can take, like: wire, wireless, optical etc. These medium are subjective to various damages such as wire cut, power failure of a node and other human generated errors. As a consequence, the sender of data from one end of communication channel could not send the data. DTN, to some extent, eradicates this problem. How TCP works? TCP is the most widely used protocol in the history of computers, that's for sure. Lets just have a look on its basics in the figure below. The main concept here is to confirm that a communication channel exists from sender to the receiver. That is exactly how TCP functions. The sender first sends a packet having SYN flag value high(1). The SYN high flag means a node wants to start a dat
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Chapter 2: Footprints

Foot-printing is an art of gathering minute details of the target like IP, OS, Software installed, Security Systems, Location, Owners, Emails, Personal data etc. A hacker gathers all the details needed to break into the system. There are numerous ways to do this and also various tools and tricks available for this. Lets discuss some of them so that we can have some idea of what foot-printing is. Foot-printing can be categorized into two types on the basis of access mode. a) Active Mode b) Passive Mode                                 a) In Active Mode , the attacker makes actual contact with the target system. The active method includes process such as email tracking, website mirror, server confirmation. Email Track : Examine email path from where is email coming, the IP, the path it took. Tools like Email Tracker Pro (Link at bottom) provide such details. these details are used to trace the fake mail's source IP's, location and path. For this tracking, the email he
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Chapter 1: Introduction to Ethical Hacking

Hacking is an unauthorized access into a system of any kind. By the word any kind, I literally mean any, any kind, be it a digital system or one without even a single digital component. The suitable name for one who breaks into computer's hardware or software is "Cracker", but in general use hacker is the term that has got more attention.  Ethical Hacking Hacking made ethical is ethical hacking. The expert computer crackers are called on for deliberate hacking attempt by the authorities of an organization, in order to test their own security level to be aware of their own vulnerabilities. Thus, ethical hacking is hacking a system to know its vulnerabilities by gaining full authority from concerned organization for such an attempt. In today's world of cyber-crime, almost every organization, business need security. The best way to be secured is to think in the way as that of attacker. Thus, ethical hacking is soaring in importance and hence the popularity.  Types
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Analog vs Discrete vs Digital Signals

Hello, everybody. We all have at least heard the terms analog, digital and discrete. In today's era of modern technologies, we, knowingly or unknowingly, use accessories whose functioning blocks are based on above-mentioned terms. So, it's quite important for us to know the meaning of those terms and also the significance they carry. Analog Signal Analog signals are the signals which are continuous throughout the time axis and can have any value of amplitude. Thus, an analog signal is continuous in both time and amplitude which means it has a value at every timestamp and the amplitude can be anything. For reference, look at the image below. Forgive me for my bad drawing but I think it will be enough to understand. In this image as we can see, the signal has value at every timestamp. If the time axis is measured in seconds, we can get the value of the signal at 3.6575528 seconds also because the signal is continuous in time. Also, there is no curbing in amplitude. Amplitu
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Sublimate the Torpor: Turn it productive

Hello, everybody! How are you all? It's been two days that I have not updated my blog. Well, today I am going to write about my last two/three days. Past two days, literally, I have remained dull and inactive. These two days must be the most inactive days I experienced in past 6 months. I am having free time at home these days as I am on the night shift at my job currently. So, there is not pretty much to do at daytime. I recently appeared GRE and thus have no academics to study too. Now I am planning to take TOEFL test within a month which will complete all the tests that I need to appear in order to apply to colleges of USA. So, just ruminating on how to utilize my leisure time, I thought to build up myself for TOEFL. One aspect of mine I really need to improve is my English-speaking. So, I decided to watch some Hollywood movies which could help me develop my speaking, listening abilities as well as can help me improve my ascent. These few days, I watched few movies plus an epi
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Brief Background Of Culture of Nepal

Today's Nepal is a unified Nepal. Present Nepal is the result of the unification of 46 smaller kingdoms. This unification was carried by the then His Majesty King Prithvi Narayan Shah. Nepal is lauded worldwide for its remarkable cultural practices. Today we will look how the present art and culture of Nepal came into existence and how its continuous development of took place in various instances of history. Three to four thousands year ago, the Neolithic matriarchal groups of Mongol, China and Bhote entered today's Kathmandu Valley. Since the Kathmandu valley was a lake then, these group settled themselves in the higher region of the hills surrounding the lake. Some of these places were Sankwo(today's Bajrayogini) and Puchwo(today's Phulchowki). The primary means of living were hunting and livestock. They also killed humans for meat. Only after learning the making of pots, these savage group started decreasing their nomadic behavior. Gradually they learn to start
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GRE & It's Hidden Benefits

Hello, everybody! I was engaged in my test preparation which I appeared today. So I didn't write in last few days. With an expectation of being forgiven, let's begin our conversation on today's topic which is regarding a competitive test naming GRE( Graduate Record Examination). In this text, I will talk about the objective of such tests and the value they add to the test takers. The GRE test basically consists of an AWA(Analytical Writing Analysis) section, a Verbal Reasoning section, and a Quantitative Reasoning section. The AWA section asks us to write on an issue and on an argument. So a total of two essays is to be written in AWA. The Verbal Reasoning section consists of "Text Completions" by filling the blanks with appropriate option, "Sentence Equivalence" by choosing an appropriate option after reaching a conclusion based on analysis of given text, "Reading Comprehension" which consists of a passage and few questions related to the pa
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