CN LAB

Computer Networks

1. Character Stuffing
2. Bit Stuffing
3. Cyclic Redundancy Check
4. Dijkstra's Algorithms 
5. Distance Vector Routing Algorithm
6. RSA Algorithm

Operating Systems

Operating Systems

CPU Scheduling Algorithms

1. First Come First Serve (FCFS)
2. Shortest Job First (SJF)  [No pre-emption, with arrival times] Shortest Job First (SJF) [Pre-emptive, with arrival times]
3. Round Robin
4. Priority

Page Replacement Algorithms

1. First In First Out (FIFO)
2. Least Recently Used (LRU)
3. Optimal

Page Replacement Algorithm

FIFO Page Replacement Algorithm

 //FIFO PAGE REPLACEMENT ALGORITHM  
 #include <stdio.h>  
 #include <conio.h>  
 int main()  
 {  
   int n, rss, fa[20], rsa[50]; //n-No_of_Frames  
   //rss->Reference_String_Size::fa->Frame_Array  
   //rsa->Reference_String_Array::ta->Temporary_Array  
   int i,j,k,pfc=0,npf, cp=0;  
   //cp->Current_Position :: ff->Frames_Filled ::pfc->Page_Fault_Count  
   //npf:NO_Page_Faults [0-False, 1-True]  
   printf("Enter number of frames: ");  
   scanf("%d", &n);  
   printf("Enter number of pages in reference string: ");  
   scanf("%d", &rss);  
   printf("Enter Reference string:\n");  
   for(i=0; i<rss; i++)  
     scanf("%d",&rsa[i]);  
   for(i=0;i<n;i++)  
     fa[i]=-1;  
   printf("\nCURRENT_PAGE\t\tPAGES_IN_FRAME\t\tPAGE_FAULT_OCCURED?\n");  
   for(i=0; i<rss; i++)  
   {  
     printf("\n\t%d\t\t",rsa[i]);  
     npf=0;  
     for(j=0;j<n;j++)  //Checking for the page in FRAME ARRAY  
     {  
       if(fa[j]==rsa[i])  
       {  
         npf = 1;  
         printf("\t\t\t\tNO");  
         break;  
       }  
     }  
     if(npf==0)   // if page fault occurs  
     {  
       pfc++;  
       fa[cp] = rsa[i];  
       cp=(cp+1)%n;  
       for(j=0;j<n;j++)  
         printf("%d\t",fa[j]);  
       printf("\tYES");  
     }  
   }  
   printf("\nTotal no of pagefaults: %d",pfc);  
   return 0;  
 }  

LRU Page Replacement Algorithm





 //LRU PAGE REPLACEMENT ALGORITHM  
 #include <stdio.h>  
 #include <conio.h>  
 int main()  
 {  
   int n, rss, fa[20], rsa[50], ta[20]; //n-No_of_Frames  
   //rss->Reference_String_Size::fa->Frame_Array  
   //rsa->Reference_String_Array::ta->Temporary_Array  
   int i,j,k,pfc=0,npf, cp;  
   //cp->Current_Position ::pfc->Page_Fault_Count  
   //npf:NO_Page_Faults [0-False, 1-True]  
   printf("Enter number of frames: ");  
   scanf("%d", &n);  
   printf("Enter number of pages in reference string: ");  
   scanf("%d", &rss);  
   printf("Enter Reference string:\n");  
   for(i=0; i<rss; i++)  
     scanf("%d",&rsa[i]);  
   for(i=0;i<n;i++)  
     fa[i]=-1;  
   for(i=0;i<n;i++)  
     ta[i]=n-(i+1);  
   printf("\nCURRENT_PAGE\t\tPAGES_IN_FRAME\t\tPAGE_FAULT_OCCURED?\n");  
   for(i=0; i<rss; i++)  
   {  
     printf("\n\t%d\t\t",rsa[i]);  
     npf=0;  
     for(j=0;j<n;j++)  //Checking for the page in FRAME ARRAY  
     {  
       if(fa[j]==rsa[i])  
       {  
         npf = 1;  
         for(k=0;k<n;k++)  
           ta[k]++;  
         ta[j]=0;  
         printf("\t\t\t\tNO");  
         break;  
       }  
     }  
     if(npf==0)   // if page fault occurs  
     {  
       pfc++;  
       cp=0;  
       for(j=1;j<n;j++)  
         if(ta[cp]<ta[j])  
           cp=j; //cp->current position  
       fa[cp] = rsa[i];  
       for(k=0;k<n;k++)  
         ta[k]++;  
       ta[cp]=0;  
       for(j=0;j<n;j++)  
         printf("%d\t",fa[j]);  
       printf("\tYES");  
     }  
   }  
   printf("\nTotal no of pagefaults: %d",pfc);  
   return 0;  
 }  

Notes/Study Materials

Computer Forensics Notes/ Study Material

BTech IV I Sem (Computer Forensics) Updated
Theory	Practical
1.       1.   Unit I Part I         Download 2.       Unit I Part II       Download 3.       Unit I Part III     Download 4.       Unit II Part I       Download 5.       Unit II Part II     Download 6.       Unit II Part III   Download

New Android Malware infects 10 million Android Devices 

More than 10m devices running Google’s Android OS have been infected with HummingBad – a new piece of malware that is able to take over a smartphone or tablet, steal and sell on user data, including banking information and other data for identify theft. It is also able to download unauthorized apps and tap on advertising.

Security firms have been tracking the malware for the past few months. According to their statistics, after a spike in infections in May, HummingBad has now passed the 10 million mark. Security experts explain that it can infect an Android device if the user browses the infected website, in so-called “drive-by-download” attacks. After this, the malware tries to gain access to the underlying Android system by using “root access” to take full control. If it fails, it attempts to trick the user into giving almost full control via a fake update alert.

Once HummingBad has control of the Android smartphone or tablet, it can force it to download apps and tap on adverts in order to generate fraudulent advertising revenue without the device owner’s knowledge. Besides, the hackers could sell access to the device or the user’s data. Infected devices have been detected all over the world with 1.6m devices in China, 1.35m in India, 288,000 in the US and 100,000 in the UK and Australia. Google admits it has been aware of that malware and is constantly improving Android, actively blocking installations of infected apps.

Nowadays, smartphones are increasingly popular, so malware targeting both Android and iOS has increased in volume and effectiveness. In response, the platform developers made further moves to protect devices from such malware. However, in this case Apple has had more success in getting users to upgrade to the latest and most secure versions of its operating systems thanks to its control of both hardware and software. As for Android updates, it can take months if not years, because Google does not directly control most of the devices.

Google has recently separated security patches from the rest of the operating system, and now security updates are pushed out on a monthly basis for its own mobile devices. At the same time, other Android manufacturers like Samsung and LG promised to do the same. However, many other manufacturers are slow to release updates to user phones, which leaves users exposed.

If your device is infected with HummingBad, a factory reset might be the only recourse. Moreover, even then it could remain.

Think of your account

Oculus CEO’s Twitter Hacked

witter account of Brendan Iribe, the CEO of Facebook’s virtual reality headset maker, Oculus, was hacked a few days ago, which made him the latest in a long line of important figures to have had their social media accounts breached.

Iribe’s account was taken over several days ago, with a tweet being sent out to his 16,000 followers announcing that Oculus is very excited to announce “its CEO – @Lid“. After this, the hacker @Lid went on to tweet at users and chastise Iribe for using the same pass for 4 years. Iribe’s Twitter account was reclaimed within hours, after the hacker tweeted that he could give it back in exchange for a free oculus rift “so i watch porn the cool way”. It is unknown if Iribe gave in to this demand.

In the meantime, security experts point out that it wasn’t as bad as it could have been for Iribe – in fact, it was more embarrassing than offensive. Anyway, the recent breach once again demonstrated the importance of account security for various online services. Recent account takeovers also included Mark Zuckerberg, Katy Perry, Channing Tatum, Twitter’s former head and Google’s CEO. Security experts continue to warn against trusting interconnected services and weak security, including using an old password.

Forensics

Businessman Sued Apple for $10bn over Stealing a Smartphone Idea
A $10bn lawsuit was filed against the iPhone maker, where Thomas Ross claimed that Apple’s mobile devices infringe his 1992 invention of an Electronic Reading Device. Ross admits that he knows he is fighting a goliath, but believes he has a strong case.

Thomas Ross claims that he worked on the invention for more than a year, drawing on his experience as a software consultant. His efforts resulted in 3 hand-sketched technical drawings of the Electronic Reading Device and filing a patent in 1992.

The invention was conceived as a reading and writing device, with a back-lit screen, able to store media on the device and on remote servers. Ross, who now works as a manager at a law firm, filed a patent 4 years before the Palm Pilot launched and 15 years before the first iPhone. The Electronic Reading Device was conceived to allow one to read stories, view images and watch video on a flat touchscreen, having communication functions like a phone and a modem, and would come with rounded edges in various sizes.

Aside from the 3 hand-scribbled images of the Electronic Reading Device, the inventor also created a flowchart illustrating how media could be requested and downloaded from a remote server along with a description of the purpose, look and feel of the device. However, that invention has never been taken further than the design stage due to the lack of funds. Back in 1992, the inventor failed to pay the required fees and had his patent application declared abandoned 3 years later by the US Patent and Trademark Office. Instead of using patent law, he now sues Apple with copyright law.

A year ago, Ross’s lawyer sent a cease and desist letter to Apple, requesting them to stop distributing the infringing products. Apple responded that the claims “have no merit” and pointed out that Ross was not able to show any evidence that Apple had accessed the patent applications. However, this response didn’t deter Ross, who filed the lawsuit with the US district court, seeking $10bn in damages and demanding Apple to forfeit the patents derived from his designs.

Industry experts call it just a nuisance case filed by an individual hoping to make some money out of it, who doesn’t even have a US patent and just pulled a $10bn number out of nowhere.

I B.Tech I Semester

S.No	Name of the Subject	Youtube links	Online Resources	Youtube
1	Computer Programming		C link

I B.Tech II Semester

S.No	Name of the Subject		Online Resources	Youtube
1	Data Structures		DS link

II B.Tech I Semester

S.No	Name of the Subject		Online Resources	Youtube
1	Mathematical Foundations of Computer		MFCS link
2	Advanced  Programming in C++ and Java		C++ link JAVA link

II B.Tech II-Semester

S.No	Name of the Subject		Online Resources	Youtube
1	Digital Logic Design & Computer Organization		DLD Link CO link
2	Database Management Systems		DBMS link DBMS link
3	OOPS Through PYTHON		PP link
4	Operating Systems		OS link
5	Design and Analysis of Algorithms		DAA link

III B.Tech I-Semester

S.No	Name of the Subject		Online Resources	Youtube
1	Principles of Programming Languages		PPL link
2	SOFTWARE ENGINEERING		SE link
3	OPERATING SYSTEM
4	DATA COMUNICATION &COMPUTER NETWORK		DCN Link
5	COMPUTER FORENSICS		CF Link
6	MICROPROCESSOR&INTERFACE

III B.Tech II-Semester

S.No	Name of the Subject		Online Resources	Youtube
1	Object Oriented Analysis & Design		OOAD link
2	Compiler Design		CD link
3	Network Security		NS Link
4	Web Technologies		WT link1 WT link2 WT link3
5	MANAGERIAL ECO.&FINANCIAL ANA.
6	VLSI Design

IV B.Tech I-Semester

S.No	Name of the Subject		Online Resources	Youtube
1	SOFTWARE TESTING METHODOLOGY		SE link
2	LINUX PROGRAMMING
3	COMPUTER GRAGHICS		CG link
4	CLOUD COMPUTING		CC Link
5	DATA WAREHOUSING &DATA MINING		DWDM link
6	INFORMATION RETRIVAL SYSTEM

IV B.Tech II-Semester

S.No	Name of the Subject		Online Resources	Youtube
1	Scripting Languages		SL Link1 SL Link2
2	Storage Area Network		SAN Link

Physicist Can Predict Wars Using Mathematical Algorithms

Wars can often seem like series of random events and attacks without any pattern or reason behind them. Surprisingly, physicist Sean Gourley and a team of researchers have found a mathematical equation that can be used to not only model past wars perfectly, but that can predict the trends of attacks in future and ongoing conflicts. Sean began the project hoping to create a database from various sources, to accurately collect every piece of news that occurs. What his team didn’t expect to find was a pattern in the attacks of wars, all related down to one very simple equation. This TED talk is incredibly fascinating, and as it turns out, all wars actually follow the exact same trend.

Gourley reports that the path, leading up to the conclusion he and his interdisciplinary team drew, was not an easy one. Finding trends within warfare and insurgency overlaps many academic disciplines, so many in academia created a lot of friction to the project as it didn’t really have a home in one subject. Gourley claims that he was criticized for not focusing fully on the discipline he was good at, but also learning about other disciplines which he didn’t know enough about, according toOzy.

His research on warfare found that all conflicts had a downward trend with a slope around 2.5. This related the number of people killed in an attack to the number of attacks for a given death toll. At first this data seemed random, but they found that when plotted on a logarithmic scale, it resulted in an almost perfect descending trend.

Iraq was the first conflict they looked into, but as they began digging deeper into past conflicts, they found that nearly every war in history yielded the same exact results. As they plotted more and more wars, all of the data clustered around a slope of 2.5, meaning that there was some kind of similarity between every known human conflict. The equation is as follows:

P(x)=Cx-α

P is the probability of the event, x is the number killed, C is a constant, and α is the slope of the conflict’s trend line. This is a surprisingly simple equation that in theory describes every human conflict that will ever take place, or has ever taken place.

[Image Source: TED]

As they thought about these numbers more, they determined that α is really the structure of the insurgency in a war. Using this formula, Gourley claims that governments and military organizations should be able to develop strategies all based around how to change the α value, therefore potentially ending a war. A conflict that will continue, maintains a slope of around 2.5, so the key is to find some way to push that trend either higher or lower. Pushing α higher would mean fragmenting the insurgent groups and making them weaker, eventually leading to a cease fire in conflict. Pushing α lower would mean pushing groups together, making them stronger and more robust, but capable of being defeated.

For the most part, this research has yet to be adopted by military powers to predict and organize attacks, but through further study, it could become a driving factor in war strategy. The goal should ultimately be to end conflicts, and through mathematical planning and calculations, finding the pathways to those “cease fires” may just become a little easier.