How to encrypt a string of text so that the encrypted string is different every time, even if the value is the same

Question

I want to encrypt a string of text safely and each time to encrypt a string, but always be able to decrypt.

For example, if I encrypt the text “FooBar” twice, I want the encrypted string to look different every time, how would I do it?

Also, what is the safest type of encryption I can use for this?

I want to use C # .Net if possible, but I am full noob encryption!

thank

Answer 1

I want to encrypt a string of text safely and each time to encrypt a string, but always be able to decrypt.

This is an extremely common requirement.

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Answer 2

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Answer 3

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Answer 4

, :

static int count = 0;

string textToSend = ...;
string textToEncryp =  count.ToString("D4") + "." textToSend;  // prefix with "0021."
count++;

// encryp + decrypt

string decryptedText = ...;
string receivedText = decryptedText.Copy(5);  // remove "0021."

Answer 5

For encryption with C # see http://msdn.microsoft.com/en-us/library/system.security.cryptography.rsacryptoserviceprovider.aspx .

If you want to save the password, this speaks about it. fooobar.com/questions/19005 / ...

Answer 6

You can use DateTime.Now.Ticks as salt.