Archive for the ‘Security’ Category

01
Jun

cryptography………

No commentsSecurityJune 1st, 2010

what is cryptography????………
Want to save  your accounts,messages,personal deatails…….. from others  cryptography may help u.Cryptography is a technique through which the message to be send are encoded in some other format so that an un-authorised user may not acess the original message.
The origin of cryptography is usually dated from about 2000 BC, with the Egyptian practice of hieroglyphics.
Cryptography can be defined as the conversion of data into a scrambled code that can be deciphered and sent across a public or private network. Cryptography uses two main styles or forms of encrypting data; symmetrical and asymmetrical. Symmetric encryptions, or algorithms, use the same key for encryption as they do for decryption. Other names for this type of encryption are secret-key, shared-key, and private-key. The encryption key can be loosely related to the decryption key; it does not necessarily need to be an exact copy.Asymmetric cryptography uses different encryption keys for encryption and decryption.he asymmetrical cryptography method has been proven to be secure against computationally limited intruders
goals:data security,data authentication,data integrity,data confidentiality
simple representation:plain  text—>encryption—>cipher text formed—>decryption—>text retrieved safely
several new cryptographic techniques are available………

01
Jun

Steganography

No commentsSecurityJune 1st, 2010

Do you know what is Steganography?

Steganography is the method of hidding message in such a way that no one apart from the sender and the intended recipient can view the message.The word steganography means concealed writing..

a small comparison with steganography and cryptography..

  • the goal of cryptography is to make data unreadable by a third party,
  • the goal of steganography is to hide the data from a third party

With computers and networks there are many other ways for hiding message which include

  • covert channel
  • hidding text within webpages
  • null ciphers

The following formula provides a very generic description of the pieces of the steganographic process.

cover_message+hidden_message+stego_key=stego_medium.

Image steganography:technique to pack the hidden message into insignificant bits in  image data.

Audio steganography:here hide the message inside an audio file.Here the messages can be embbeded using LSB algorithm.

LSB Algorithm:

  • select an audio file
  • secret message is embedded at the least significant bit of the audio file
  • sender and recipient share the secret key.
  • in destination as soon as the audio file is got,the message will be stored in a buffer
  • the message can be retrieved only by using the stego_key