encryption

: encryption... if communication iz encrypted for transmission over different channelz ... 1 side data iz encryption done and other side decryption.... so how decryption would do,how the system will know properly dat how the data waz crypted and then to decrypt , in case of windowz system , ... if tiz done hidden from hacker ... receiver has windowz and the hacker has too... both Os can do theze all...
i am confuse in cryptography .. plz any1 help me with example...

Encryption is a very simply concept which often uses not so simple methods to create security.The basic idea behind encryption is your trying to make data sent "cryptic" (hard to understand) to people who you don't want getting the message.

So lets try an example!
I want to send you the message: This is the Windows and Dos Forum not the Basic Concepts forum

I could do that very easily just by telling you. The problem is that is kind of an embarrassing to recieve publically and were using a public medium the windows and dos forum.So to obstruct prying eyes I tell you I'm encrypting the message by subtracting one letter to every character so that hopefully only you get the message with the new encrypted text of:

Sglr lr sgd Vlmcnvr bmc Cnr Enqtl mns sgd Azrhb Bnmbdosr Enqtl

Now if everyone was watching me give the decryption method that that encryption wouldn't do a whole lot of good generally speaking. Granted even without that hit some people on this board would be able to figure out such a simple encryption without prompting. Because encrypting information is very important and people work hard to decrypt information many many forms of encryptions have been created.

Be warnned encryptions can be intense and speaking in general terms the innerworks of advanced encryptions are mostlikely out of the scope of what you'll need to know. Mostlikely you'll want to focus on knowing requirements for WEP, WPA and WPA2 and thats about it.

This example shows how cryptic **** AES **** a common encryption method
really is.

Good effort Nevins

Great and simple example Nevins.

so how decryption would do,how the system will know properly dat how the data waz crypted and then to decrypt

Most current encryption methods have two parts. 1st, an encryption algorithm, which is known to the public and is built into the system (like windows). 2nd a secret key (a number) which is known ONLY to the two users communicating. The same key is used to encrypt and decrypt (it's called Symmetric Encryption). And this is the answer to your question, the systems (windows) doesn't know the key, only the two users know it. One example of such an encryption method is DES (Data Encryption Standard) which uses a 56bit key.

There is also Asymmetric Encryption, Like RSA. RSA uses two keys, one to encrypt, the other to decrypt. It's like a door lock with two keys. Once you lock it with one key, you can only open it with the other key.

thanx Navins & Solo

Still unclear to me ,,,
i studied different Algoz about Encryption
i got it but but but problem iz to know how 1 site done encryption and other side decryption ...
what i mean? lets me explain
if encryption done and it z know the key/z and it be sent to target site 4 decrypt ... if the da person will send exact key to receiver ... might be on phone or otherz) but
v see dat usually v dont do like it ,,, so
then how sender sharez key wit receiver ...
how receiver systen will know to back the original data by decryption ... (if theze all siittled down Already in receiver'z OS/browzer then hacker also have thiz knida )

( if private key iz in sender pocket and public key iz sent to target receiver ... how iz it sent to receiver ... ?)
and today which kinda encrytion iz implemented on internet or n/w envorment )

(


plz plz any1 will get wt i mean to know how to make my concept about public/private keyz sharing on internet or n/w)

?????

if encryption done and it z know the key/z and it be sent to target site 4 decrypt ... if the da person will send exact key to receiver ... might be on phone or otherz) but
v see dat usually v dont do like it ,,, so
then how sender sharez key wit receiver ...

In fact thats a very good question. When using public/private keys (As in RSA or SSL). like for example, when you want to buy some thing on the internet and the site page would encrypt your credit card number before sending it. The person does NOT NEED to send any key, the target site sends it's PUBLIC key to the person's PC. The person's PC uses this key to encrypt the credit card number and sends the encrypted data to the site. The site now will use it's PRIVATE key to decrypt the data. Now, even if there was a hacker who listened to the PUBLIC key, he will NOT be able to decrypt the data because he does NOT have the PRIVATE key of the site.

This process encrypts only the data going from the person to the site, not the data from the site to person. But it's usually OK because the persons data (credit card) is in most cases the most important data. We usually don't care if the hacker sees the site's data. This is the reason you usually don't need to give your key to the site.

If you want to encrypt the site's data, the person will also need a private and public key. He will have to send his public key to the site (no problem if the hacker catches it). The site will then use it to encrypt then send, then the person will decrypt using his private key.

I hope this helps. I tried to simplify this and talk extremely basic English here. There is more to the subject than what meats the eye.