Time and Space Complexity Tutorials & Notes | Basic Programming | HackerEarth
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In this case the person who was attacked scoured the log files of his computer network to reconstruct the attack, having understood it he was then able to use his reconstruction to demonstrate that an IP spoofing attack had happened [ 5 ].
A day zero plus one or more exploit is the utilisation of an existing technique. For example, someone seeing Shimomura present a talk about the attack on his network, who then explored the Internet and found further theoretical documentation of how to do such an attack, could then try to find targets and launch an attack.
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They may well also seek advice from other crackers, through online fora or in chatrooms. Though lacking the absolute originality of a zero—day exploit, running day zero plus one exploits often requires a significant level of expertise and innovation within known vulnerabilities.
Social engineering is the cracking of computers without computers. Classic techniques include trashing or dumpster diving looking through rubbish bins for information ; shoulder surfing; and roleplaying tricking people into giving out their details. As Wall has argued, social engineering has moved into automation. Wall has identified the automation of social engineering. One example is when hacked Web sites open up, unrequested, a window that tells the user their computer is likely to be infected with a virus.
Then, no matter what the user does with this window, a graphic automatically opens up which shows a virus scan being run on the computer. This scan is actually doing nothing, it is simply a graphic but it appears legitimate and at its finish it tells the user it has found an infected file and then, again automatically, asks the user to install software to clean the computer. The supposed programme is in fact itself a virus, not a virus—removal, and installation will then infect an uninfected computer.
Though this example uses network technologies and computers, the essence of the hack is social in its attempt to trick a user into infecting their uninfected PC [ 6 ].
Script—kidding involves taking known exploits and automating them. This reduces the knowledge necessary to launch an attack to the pressing of buttons on gui programmes. For example, there is a programme called BackOrifice that automates installing Trojan programmes on a Microsoft network, allowing the person using BackOrifice to act as a systems administrator and view all that is happening across a network [ 7 ].
We can already see that at heart cracking is about taking a social ambition to control a computer or network and reordering technologies to fulfil that ambition, while at the same time starting from a technological basis only being able to take certain actions due to the technologies to hand from which only certain social ambitions may be realised.
Cracking is about using social norms to determine technological constraints and it is about using technological determinations to cause different social norms. We can also see that across the four types of crack there is both a reliance on knowledge and a willingness to embody knowledge. This combination refers us to the community of crackers in the connection of peer education and peer recognition that occurs in cracking and that gives cracking its dynamism.
Peer recognition refers to the ways crackers validate each other as members of the cracking community, a process that exists in some form in all communities. Crackers have particular difficulties creating a process of recognising other peers because it can be difficult to prove the things they have done; it is easy for a cracker to claim they entered a particular site or invented a new technique, but how can they convince other crackers?
The primary way of solving this problem is to explain techniques, which may be portable techniques that new crackers can take off to test or may be techniques specific to a particular site. If the proof of doing something is, fundamentally, showing someone else how to do it then inevitably crackers are drawn into not just explaining something once but coaching others into repeating the crack.
In this way a form of peer education is intimately tied into one of the basic processes of any community — how to recognise other members. Crackers who wish to remain secret can do so but they run the risk of being excluded from their community; for example, losing chances at being enrolled in secured chatrooms or simply missing out on elite pizza—eating contests at conferences.
The only alternative to secrecy and the only consistent and convincing way to peer recognition for crackers is to teach other crackers.
This embeds a strong dynamic within cracking that constantly drives techniques and exploits upwards. This drive to greater complexity means that crackers are always attacking the existing state of technology and re—ordering it at the everyday level. One of the few quantitative academic investigations of cracking demonstrates this upward spiral by analysing reports to CERT http: Howard created a taxonomy of security breaches and analysed CERT records between — The two trends in severe attacks that he identified were: The second trend was that intruders became increasingly difficult to locate and identify.
This everydayness of cracking is an important quality and the ephemeral nature of cracks is one consequence; defaced Web sites can be repaired by copying backed—up files, often in minutes; sites removed from the Internet by denial of service attacks are usually back again within hours or a day; cracked open networks can be patched, requiring new exploits.
This makes crackers like ghosts, constantly interacting with technology, having their own actions determined by the technologies they are using while revising the technologies of others but all at an everyday level. Crackers cause and are caused by intermingled technological and social determinations. This intermingling of social, technological and determination is a dynamic we will see repeated in the second key component of hacking, the free software and open source movement FOSS.
Hacking, free software and open source software The free software and open source movement FOSS always existed alongside crackers but was for a time barely in public view, particularly during the early s when sensational accounts of cracks dominated media understandings of hacking.
However, in the last 10 years the understanding of hacking as programming has become important again. Here we find experts making programmes in collaborative and open ways, with a novel understanding of property.
Such programmes are significant particularly in the backrooms of IT, where they construct much of the virtual world; for example, BIND is the dominant DNS server and Apache runs around 60 percent of Web sites Netcraft, On top of these numbers are some qualitatively important programmes such as the Emacs text editor and the GNUC compiler. Two quick examples will help to stake out the territory occupied by FOSS.
Both Linux and Apache are collaborative software writing projects. Apache began when a number of administrators of existing Web sites met to improve their work and began to integrate different programmes they were using. From this beginning a collaborative network of programmers developed which contributes code to the ever developing Web server programme called Apache. Programming is distributed among volunteers, who may also work for corporations willing to donate programmer time, but decisions are controlled through a council and formal voting rules [ 9 ].
Linux began as a project by Linus Torvalds to add some functionality to an existing programme of his a terminal emulator. Torvalds released the Linux kernel and from the beginning began to receive corrections from other users that he was happy to integrate.
The massive programming efforts that characterise Linux, Apache and a series of other programmes — from full office software suites in OpenOffice, to powerful graphics programmes in GIMP and so on — are part of a movement and community. I have adapted these three to community, object and property because I believe that politics permeates property and community to such an extent that it cannot be sensibly separated.
I also think that Weber underestimates the role of the object of programming. Free software and open source programmers often refer to themselves as being part of a movement or a community and they may well discuss how one of their defining characteristics is total access to source code, both to view and change it.
Source code refers to the series of instructions that make up any functioning software programme, access to the code means access to the ability to fundamentally understand how a programme works and to intervene into the programme changing how it works.
This access creates the FOSS characteristic of voluntary selection into tasks that are perceived to be important, interesting or likely to generate esteem. The community is composed overwhelmingly of those who can programme and so presumes a quite particular form of expertise. One often under—appreciated facet of FOSS is the way it has a particular object around which there are possibilities for the resolution of social and technological debates.
How do the communities of distributed, collaborating experts organise themselves to focus on particular projects and so to achieve things like Linux or Apache? That the object is a software programme whose inner workings are open to change means that FOSS produces a dynamic relationship to the opening and closing of its particular technologies.
This dynamism is driven not just by collaborating experts who have a particularly protean form of technology at their fingertips but also derives from the third component of FOSS, its re—conception of property.
As Weber argues, FOSS is fundamentally organised around property as the right to distribute, in opposition to our normal notion of property as the right to exclude.
We usually use property relations, and all their attendant institutions such as law courts and the police, to exclude people from using the things that are our property; my car can only be used by myself and those I offer it to, I control access to my house [ 11 ].
This is particularly in relation source code and the right to change source code but it also requires that any changes to source code have to be redistributed to the world. The moment of inversion is that someone who owns a programme effectively claims: The most famous such licence is the GNU Public Licence of which there have been three versions but there are others.
Taken together the trio of community of experts, resolution through objects and property as distribution define a powerful engine for programme production, which also embeds within itself the nature of digital objects. As with cracking we see in FOSS a constant interaction of technology and society, including moments of determination and being determined. A FOSS hacker can take a particular technology, in the source code of a programme, and so be determined by what that code allows but can then, because they have expertise, community support and access to the code, start to alter the programme thereby injecting various social imperatives within that technology, and so redefining whatever determinations will affect a subsequent user of that programme.
While the making and unmaking of social and technological determinations occurs in the everyday moments of programmers typing on computers to churn out code and then passing such code around to be integrated into programmes, the result has been a wide range of programmes that form much of the infrastructure of digital life like my use of OpenOffice to write this which is in turn running on top of a version of Linux which is in turn reliant on BIND, among other programmes, to connect to the Internet.
This is clearest in the internals of the Internet, where many FOSS programmes are found running in ways invisible to most of us. Cracking and FOSS create the core relations of hacking, both of them engaging in varied and contradictory ways with society, technology and causation, one primarily at the everyday level of computers and networks and one primarily within digital infrastructures.
It is this intermingling of social and technological determinations that marks out the dynamism of hacking and its broad social significance. Hacking the social and hacking the non—hack Between cracking and FOSS we have the core of hacking in their joint explorations of how to engage in social and technological determinations of computer and network technologies and socialities, but this is not all there is to hacking.
Around the material practices of crackers and FOSS hackers there are a range of other activities that demonstrate the breadth and richness of hacking. I will group these roughly under the two headings of hacking the social and hacking the non—hack and briefly introduce them. Hacking the social refers to groups that take up the interaction of technological and social causation in computer and networked technologies created by hackers and who then apply it to changing society.
Instead of playing within constantly revised determinations of technology and society, some take the ability to make such revisions and apply it to making social change through political activism, war, terrorism or crime. Hacktivists are political activists, most often associated with the alter—globalisation movement, who utilise hacking techniques to create grassroots activist political campaigns.
Hacktivists produce both ephemeral electronic civil disobedience actions, such as blocking online sites with mass electronic action, and they try to create infrastructures of secure anonymous communication often to support human rights workers Jordan and Taylor, Cyberwar is the use of cracks by one nation—state against another nation—state.
For example, it is widely believed that the Chinese government has been hacking both the U. Cyberterror is the use of cracking techniques in a strategy of seeking social change through attacks that produce psychological as much as physical damage.
There are almost no recorded cyberterror attacks, though the potential for damaging communication systems, infiltrating civilian infrastructure or attacking military targets seems clear Verton, ; Weimann, Finally, cybercrime is the use of cracks to generate personal gain, usually financial gain.
The second cluster of activities related to hacking I have termed hacking the non—hack and they particularly help to see the boundaries of hacking, for example by separating programming from hacking. There are three groups here. The first group is the Creative Commons, largely based on the arguments and organisation of Lawrence Lessig A second group are non—programmers.
Here is hacking without programming. The third group is the programming proletariat who, like most FOSS hackers, programme the code that makes up software programmes but, unlike FOSS hackers, do not choose or control which technological and social determinations they engage with.
Here is programming without hacking Bronson, Three points emerge from considering these seven groups that draw on the central dynamics of hacking. Second, we can see boundaries being drawn around hacking but these boundaries cannot be simply equated with programming or software.
Rather, we have seen programming non—hackers and non—programming hackers. This means it is important to keep in focus the dynamics of hacking when trying to understand what hacking is, as opposed to some of the obvious markers of hacking such as, programming skills. Finally, the example of Creative Commons emphasises that it is the protean nature of programming that underpins the dynamism hackers can give to determining and redetermining.
Creative Commons shows this when it develops non—hacking positions because of the different nature of its object. With artistic products, what is finished is perhaps finished when the artists says so and a revision is an entirely new object, not a revised or 1.
For this reason Creative Commons allows what is rejected in FOSS in a license that says you can take but cannot change the content of the object. Software continually develops or can be developed while remaining the same object, whereas the re—use of words or sounds of a poem or song tend to create a new poem or song. Such malleability while remaining the same thing is one factor underlying the simultaneous and contradictory determinations of society and technology that lie at the heart of hacking.
It is because crackers and FOSS programmers can constantly take a particular software and then open it up that they can be determined by a technology as they simultaneously re—determine what the technology can do.
We now have the whole of hacking before us in the central dynamic produced by cracking and FOSS, with the various groups who hack the social or hack the non—hack.
We can also see that this central dynamic is based on the nature of software and programming, that it can be politicised in non—hacking ways though the notion of determination and that the boundaries of hacking are determined by this dynamic and not by what are revealed as more superficial definitions such as whether someone is a programmer or not.
Having reached this position, we can now turn to look at how all this relates to our understandings of technology and society in the information age.
The starting point for such an analysis can be most usefully made by returning to the concept of technological determinism. Such views have been widely disproven across the social sciences, for a number of reasons but chiefly because they position technology outside of society and extended work in the social studies of technology and science demonstrates that technologies are as much social enterprises as anything else Mackenzie and Wajcman, Yet despite the widely accepted refutation of technological determinism that social studies of technology offers, hacking suggests a difficulty with views that fail to take account of some kind of mutually determinative power between technologies and societies.
An absolute rejection of technological determinism in any form makes activities such as FOSS programming very difficult to understand because of the interaction between determinations that constitute it. It follows that it is important to acknowledge a problem with accounts of technology that imply or argue that technologies do not have specific material and determinative effects.
For Gibson, humans, along with animals, insects, birds and fishes, orient to objects in their world rocks, trees, rivers, etc. However, they cannot be seen as freely variable. While a tree offers an enormous range of affordances for a vast variety of species, there are things a river can afford which the tree cannot, and vice versa.
This is useful for this account of hacking because captures the sense in which technologies both are and are not open to social influence and it reasserts the influence of technology on society. It is this mutual sense of determination and redetermination that is at the core of hacking. A further aspect of Hutchby is worth drawing out as, though he does not use the term, the everyday seems to be the site of these mutual determinations.
Take a moment to consider what sort of relationship you have with time. One problem many of us suffer from is the illusion that we have unlimited amounts of time at our disposal.
From a moment to moment perspective we feel as though we have lots of time before our internal clocks cease to tick. Surely, we can spare a few? Along the way, many of us lose track of time. One reason for this is that most of us tend to appreciate things that are scarce to come by, while things like air and sunlight, go largely unappreciated.
A key to appreciating time is to view it in the context of smaller chunks rather than years, months or even days. After all, being present and fully committed to a single activity is how memorable moments are created. Respecting and appreciating time are the first steps toward reclaiming the time that slips away from you.
THM offers a different way of seeing time. At its core, the hack is to detach our perception of time from the surface of a distant goal or even a looming deadline — and instead view time in the context of a day. A day filled with a finite collection of singular blocks of time. Our efforts within each time block should be short and highly focused. As your appreciation of time grows so will your number of time blocks. During an individual time block only the task at hand matters.
All other distractions are met, quickly cataloged and temporarily discarded. The goal is to provide extreme and mostly undivided attention during that period.
Most importantly you avoid thinking about the parent task that the current task is a part of. Not doing so often leads to distractions which include fear, uncertainty, and doubt. And overthinking instead of simply doing. By limiting scope and creating context, we increase our laser focus.
To paraphrase Bruce Lee: THM consists of four phases: Determine your average working time. John begins by taking inventory of what he wants to achieve on a given day. He either does this the night before or just before he starts his day. So he has six one hour segments to work with.
Using pencil and paper or a time hacker clockJohn is able to track how many of those hourly segments remain throughout the day. Each task is ideally do-able within 15 minutes — but some tasks might take several 15 minute time blocks to achieve. John uses 15 minute timed blocks in order to remain focused on a specific tasks. John decides he needs another block but alas nature calls and he needs a short break. As John resumes another time block he centers himself and attempts to block out distractions.
He understands that presence and focus is key to achieving his goal. Every hour John pauses and considers how many one hour segments remain in his day. At the end of the day, John takes inventory of what got done and what still remains. He uses a journal to track his progress and to plan the goals and micro-tasks for the next day.
Susan might follow a similar path as John, but might instead have only three hours to devote and three goals to complete. Essentially the time I wake up until the time I theoretically should call it a day. Not per minute — instead think in terms of the most important tasks. Tasks that measurably move the needle on the gauge that measures your goals. You should only have a handful of daily tasks, ideally only three or so.
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Next, create a list of micro-tasks which will bring you closer to completing your three goals. The key here is to divide a larger task into smaller, more manageable chunks. Each micro-task should be something you can accomplish within 15 minutes of highly focused effort. This phase should be done daily in the evening in prep for the next day.