Saturday, 19 December 2015

Common Computer Threats !!!


 phishing is nothing but an attempt to acquire sensitive information such as usernames, passwords and credit card details by pretending to be a trustworthy entity in an electronic communication. it involves sending fake e-mails, text massages and creating fake websites which pretends to be official.

 Modus Operandi :

 They Trick you Through Emails or massages  into giving them your information such as bank details , password by asking you to update, validate or confirm your account.spyware is a software that displays advertisements (adware) or that tracks personal or sensitive information. 


Spyware is a software that displays advertisements (adware) or that tracks personal or sensitive information. it can change the configuration of your computer without your knowledge.

Possible Harms :

  • Collect information about you without you knowing about it and give it to third parties.
  • Send your usernames, passwords, surfing habits, list of applications you've downloaded, settings, and even the version of your operating system to third parties
  • Take you to unwanted sites or inundate you with uncontrollable pop-up ads.

Trojan Horses

Trojans can be employed by cyber-thieves and hackers trying to gain access to users' systems. Users are typically tricked by some form of social engineering into loading and executing Trojans on their systems. Once activated, Trojans can enable cyber-criminals to spy on you, steal your sensitive data, and gain backdoor access to your system. 

·         Trojan-Banker                                                                                                                                               Trojan-Banker programs are designed to steal your account data for online banking systems, e-payment systems, and credit or debit cards. 

  • Trojan-Downloader 
Trojan-Downloaders can download and install new versions of malicious programs onto your computer – including Trojans and adware. 

Sunday, 29 November 2015


What is Bitcoin?

Bitcoin is a new currency that was created in 2009 by an unknown person using the alias Satoshi Nakamoto. Transactions are made with no middle men – meaning, no banks! There are no transaction fees and no need to give your real name. More merchants are beginning to accept them: You can buy webhosting services, pizza or even manicures.

The basics for a new user

 You must install a Bitcoin wallet on your computer or mobile phone, it will generate your first Bitcoin address and you can create more whenever you need one. You can share your addresses to your friends so that they can pay you or vice versa. In fact, this is pretty similar to how email works, except that Bitcoin addresses should only be used once.


Balances - block chain

The entire Bitcoin network relies on block chain which is a shared public ledger. All confirmed transactions are included in the block chain. This way, Bitcoin wallets can calculate their spendable balance and new transactions can be verified to be spending bitcoins that are actually owned by the spender. cryptography is employed for the sake of security.

Transactions - private keys

A transaction is a transfer of value between Bitcoin wallets that gets included in the block chain. Bitcoin wallets keep a secret piece of data called a private key or seed, which is used to sign transactions, providing a mathematical proof that they have come from the owner of the wallet. The signature also prevents the transaction from being altered by anybody once it has been issued. All transactions are broadcast between users and usually begin to be confirmed by the network in the following 10 minutes, through a process called mining.

Processing - mining

Mining is a distributed consensus system that is used to confirm waiting transactions by including them in the block chain. It enforces a chronological order in the block chain, protects the neutrality of the network, and allows different computers to agree on the state of the system. To be confirmed, transactions must be packed in a block that fits very strict cryptography rules that will be verified by the network. These rules prevent previous blocks from being modified because doing so would invalidate all following blocks. Mining also creates the equivalent of a competitive lottery that prevents any individual from easily adding new blocks consecutively in the block chain. This way, no individuals can control what is included in the block chain or replace parts of the block chain to roll back their own spends.

Image result for BITCOINS EXPLAINED Why Bitcoins?

Bitcoins can be used to buy merchandise anonymously. In addition, international payments are easy and cheap because bitcoins are not tied to any country or subject to regulation. Small businesses may like them because there are no credit card fees. Some people just buy bitcoins as an investment, hoping that they’ll go up in value  

Important Virtual Currencies Other Than Bitcoins.

  • Litecoin
  • Darkcoin
  • Peercoin

  • Tuesday, 10 March 2015


    With the rise in online money transactions worldwide from recharging your mobile balance to purchase or money transfer of thousands of rupees. We should aware of online ‘thugs’. Recent study shows that every online user owes 2.80 $ to the hackers so we should know that how different mobile apps, websites try to protect our transaction details from the hackers.
    These are nothing but the encryption techniques. The most commonly used is the AES ( Advanced Encryption Standards),AES-128,192, and 265 for governments, banks and other popular apps.
    Encryption systems are of two types
    1.     Symmetric-key
    2.     Public –key
    In symmetric –key encryption ,two communicating computers have a secret key which is used to encrypt the code . and believe me AES-128 bitkey for instance can have more than 300,000,000,000,000,000,000,000,000,000,000,000. Key combinations and cracking it with a state-of-the-art supercomputer would take longer than the presumed age of the universe i.e 4500 million years. And current systems uses AES-256 so its impossible to crack AES-256.

    Ø  IT’S Algorithm.
    The algorithm is based on several substitutions, permutations and linear transformations which creates 16 byte block. Operations are repeated several timesand results into ‘rounds’. During each round a unique key is calculated out of the encryption key, and incorporated in the calculations.

    Sunday, 22 February 2015


    (1) Williamson labs. 

    it has collection of more than 400 urls in over 90 related subject areas. this website helps you to understand and imagine electronics with the help of animations and 3D pictures.

    (2) electronics tutorials.

    offering free,comprehensive basic electronics tutorials in amplifiers,antennae,filters,oscillators,power supplies,receivers,radio and electronics designes. it covers over 120 individual topics with links to datasheets,reference books and projects.

    (3) raspberry pi tutorials.

    this website offers free,comprehensive raspberry pi tutorials. helps you to program your device . tutorials are targeted at anyone who can read and has access to a computer programming language python.


    (4) mytutorialcafe.

    this website is dedicated to the MCS51 microcontroller and related products. it includes the traditional 8052,8051,8032,8031 along with more modern derivatives such as the Atmel AT89S8252, andmany derivatives by silicon laboratives,philips and others.

    Monday, 9 September 2013

    join indian air force

                                                                      Join Indian air force
    For challenging career and a bright future
     Caree prospects
    Flying branch
    Branch/type of entry

    Age limit
    (a)National defence academy (NDA)
     (pc for men only)
    10+2 with physics and maths.
    (b)combined defence service(CDSE)
     (pc for men only)
    Any graduate degree/BE/B Tech
    (c) NCC special entry
    Any graduate degree/BE/B Tech with min. 60% marks
    (appearing/final semester/year student
    can also apply)

    Technical branch
    (a)Aeronautical engineer
    Engineering degree with min.60% marks
    (b)university entry scheme
    Pre final year in engineering

    Ground duty branches
    (c) accounts
    Graduate degree with min. 60% or post graduation degree with min 50% as per ads published
    (d) education
    (e) meteorology
    Post graduation degree

    Friday, 26 July 2013

    tips for avoiding mobile radiation harms...!!

    Recently the supreme court of india had given the instructions not  exceed the no. of telephone towers on particular  building more than two , by considering the health related issues. The WHO has also issued a precautionary principles to avoid genotoxic effects,EM allergic effect & cognitive effect by the mobile phones magnetic radiations.
    Tips for reducing danger by the mobile phone radiation.
    • 1.       Use wired headset or speakerphone mode and keep the cell phone as far away from your as possible. In particular , use air-tube headset with ferrite beads as they don’t work as antenna so the risk of exposure to EM radiations also reduced.

    • 2.       Don’t allow children to use cell phone ,under 18 because the radiations can badly affect the development and maturation of the central nervous system,immune system and critical organ.

    • 3.       U can also use the patented cell phone radiation protection device.
    • 4.       Prefer the cellphone with low SAR

    • 5.       Avoid using mobile phones in a close proximity with the metals surrounding it, because the metal structures increases the radiation output of the device.

    • 6.       Don’t use the cell phones when u are travelling with fast moving vehicles, as in this case mobile sends and receives the extra signals.