Monday, April 22, 2013

problem: All exe files are opening in vlc

When you try to open any exe file or say shortcuts then it opens in vlc media player that is horrible. I have found some solutions try them .
  1.  click here  and fix it.
    If you are unable to open Internet Explorer to access the link, hit the Windows key plus r on your keyboard and copy and paste the below command in the Open Box (this assumes that W7 is installed on your C drive):

    rundll32 shell32.dll, ShellExec_RunDLL "C:\Program Files\Internet Explorer\iexplore.exe"
  2. download and install
    Fix .exe : click here to download
    install it . this works many times.

Tuesday, April 16, 2013

why you not recieving any sms from internet sms website???

Aren't you receiving any SMS from various online free daily sms sender or is you phone no more has any notifications of new sms's, that is because of change in the TRAI rule, most of them are not receiving messages from the usual sources where they used to get. The rule was passed to protect consumer privacy from SMS spammers.
You must be shocked to see such kind of errors even while sending the message from sites like Way2sms, 160by2 or any other online free sms sending sites or even from Google Labs.

SMS440.com Error: DND Number, Cant send message.
Way2sms error: Submission Failed. Mobile Number is in DND
To receive SMS from Google Channel Labs/ Way2sms/ 160by2 without any problem, you have to de-register from National Do Not Call Registry(NDNC) by sending an SMS from your mobile



STOP DND to 1909. 
Which is a toll free number and you would not be charged for sending this message.


In short it means you have registered for Do Not Call(DNC) earlier and now you are de-registering.

Thursday, April 11, 2013

Why bother to learn "C language" Today??


Now a days there  are many superior languages are available like C++, java, C# etc, then why to learn C??? There are several reasons for this , as follows-
  1. I believe that nobody can learn such higher languages like C++,java,C# directly because it has things like classes, objects, polymorphism, Exception handling etc..we can learn this complicated components easily when we are comfortable with basics. So we can learn this basics easily with C.
  2. Major parts of popular Operating Systems like windows, linux ,UNIX are still written in C.
     
  3. Embedded Systems like Microwave ovens , washing Machines , digital cameras are getting smarter day by day. This smartness comes from OS and Smart Programs . These programs not have to only run fast but also have to run in limited amount of memory. No wonder that such C programs are written in C.
  4. In 3D computer games speed is essential component. So for fastness C language scores over other languages.
  5. At time one is required to very closely interact with hardware devices. Since C provides several language elements that makes this interaction feasible without compromising the performance.   

       

Saturday, April 6, 2013

Cryptography




Cryptography

is the study of mathematical techniques related to aspects of information security, such as confidentially or privacy ,data integrity and entity authentication. Cryptography is not only means of providing information security, but rather one set of techniques. Confidentially means keeping information secret from all but those who authorized to see it. Data integrity means ensuring information has not been altered by unauthorized or unknown means. Entity authentication means corroboration of the identify of an entity.



Definition of cryptography


 Cryptography is the study of mathematical techniques related to aspects of information security, such as confidentially or privacy, data integrity and entity authentication. Cryptography is not the only means of providing information security, but rather one set of techniques.

Cryptography

Categories of cryptographic algorithm


There are main two types of cryptographic algorithm.
1: - Symmetric key
2: - Asymmetric key


Symmetric key

1.  Sender and Receiver share a key.          
2.  A secret piece of information used to encrypt or decrypt the message.
3.  If a key is secret, than nobody other than sender or receiver can read the
      message               
4.  If Alice and bank each has secret key, than they may send each other 
      private    message.
5.  The task of privately choosing a key before communication, however can 
      be problematic.
             

Asymmetric key

1.  Solves the key exchange problem by defining an algorithm which uses     
      two keys, each of which can be use to encrypt the message.
2.  If one is used to encrypt a message, another key must be used to 
      decrypt it.
3  This makes it possible to receive secure message by simply publishing one
      key (public key) and keeping another secret (private key).
4  Any one may encrypt a message using public key, but only the owner of
      the public key is able to read it.
5  In this way Alice may send private message to owner of a key-pair (the      
      bank) by encrypting it using their public-key. Only bank can decrypt it.
 


Goals of cryptography


The main goals of cryptography are
1: - Confidentially or privacy
2: - Data integrity
3: - Authentication
4: - Non-repudiation

 


Characteristics of a cryptographic algorithm


The main characteristics of cryptographic algorithm are
1: - Level of security
2: - Performance
3: - Ease of implementation