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Questions tagged [encryption-symmetric]

A type of encryption where the same key is used to encrypt and decrypt the message.

Symmetric encryption is the oldest and best-known technique. A secret key, which can be a number, a word, or just a string of random letters, is applied to the text of a message to change the content in a particular way. This might be as simple as shifting each letter by a number of places in the alphabet (known as the Caesar Cipher), or as complicated as the Advanced Encryption Standard, which is used in some modern cryptography. Anyone who knows the key can either encrypt or decrypt a message.

Note that symmetric encryption does not require that the encryption and decryption key be identical, but rather that both keys derive from the same knowledge. For example, a letter-shifting cipher might require that "A" be enciphered as "G" - the opposite operation would be needed to decrypt.

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How to put the key for image encryption using AES Algorithm

I'm newbie in java. I already have a code for AES algorithm for image encryption. My problem is I just want to add the key for my encrypt image and only the person I give the key can only decrypt the image example such as symmetric encryption,…
John U2
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Python gnupg, symmetric encryption file size bigger than if using gpg on command line

I have a 85mb tar.gz file. When I encrypt this using gpg the encrypted file size is 85 mb. When trying to encrypt using Python gnupg encrypted file size is 115 mb. That is very strange since gnupg just uses sub process to gpg to send arguments.…
vas
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Encrypt in Java and Decrypt in MS SQL Server

My application flow is as follow. JAVA APP ----> MS SQL (Tables)---> MS SQL (Stored procedure) ---> Another DB Here from Java application i am pushing certain Sensitive information that i even want to hide from DBA. So i want to encrypt those…
Nimble Fungus
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Why does generateKey method from DES algorithm multiply the key by 8?

I am in need of some explanations on the corresponding line, which I do not understand: KeyGenerationParameters kgp = new KeyGenerationParameters(sr,(DESParameters.DES_KEY_LENGTH) * 8); Would it stop working, if I had, for instance, the number 6…
qwerty
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Can One-Time-Pad key be reused if encrypted plaintext is random?

I want to encrypt purely random data with one single key that is shorter than the plaintext. Should I use AES or another robust encryption algorithm, or can I use OTP, i.e. only xoring (purely random) plaintext with the unique key, block by…
user2746222
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Encrypt String in java and decrypt it in winrt c#

How one would encrypt a string using symmetric/asymmetric decryption on WinRT Metro in C# and encrypt this in java, let's say in a webservice? I want to use RsaPkcs7 algorithm and I can see that CryptographicKey class and RSAParameters class are not…
prasanas
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Symmetric mapping of guids

Is there an existing secure implementation to achieve following: Guid original = Guid.NewGuid(); Guid inverted = MysteryImplementation(original, salt); // salt is some sort of input Guid shouldBeOriginal = MysteryImplementation(inverted,…
Fdr
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How to add more characters and letters to rot13 and Caesar encryption

I want to add the letters "ç," "ğ," "ı," "ö" and "ü" into this encrypter's alphabet, and maybe special chars, too. How can I do that? for (int i = 0; i < metin.length(); i++) { char harf = metin.charAt(i); if (harf >= 'a'…
user1489540
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how to use rsa in application i found code but dont know how to implement

HOW TO I USE THIS RSA http://xtrace.blogspot.com/2012/03/rsa-demo-example.html?showComment=1349091173502#c199333123405145467 TUTOTIAL CODE IN MY LOGIN CODE BELOW I found code but dnt know how to implement public class LoginScreen extends Activity…
Hayya ANAM
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A problem with an encryption algorithm program written in C#

I wrote a program in .NET 7 that encrypts a string and returns another string that contains the encrypted form of the first string. The problem is the program does not return anything, only a null string using System; using…
8K Tek
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How to get AES key from java code so that i can save it in a text file?

I have tried below code to get AES key from java code. And the output is also captured after the code. import javax.crypto.KeyGenerator; public class MyClass { public static void main(String args[]) throws Exception { KeyGenerator…
samshers
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How does the aes256 encryption algorithm deal with keys whose length is not equal to 32 bytes?

The reason why I ask this question is that we all know that this algorithm will fill the plaintext data into a multiple of 32 bytes, so how will the key with less than 32 bytes or more be handled? Because aes256 encryption algorithm is used in many…
user17151495
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AES encryption/decryption using EquivalentInverseCipher in C

I'm doing project in AES. Has anyone worked in equivalent inverse cipher? I am researching the underlying concept in it and how to implement in C.
arun
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PHP Encrypt and Decrypt Parameter URL in URL

I'm trying to pass a download URL from page 1 to page 2 in a GET request. Page 1 gets the raw URL through the database, then encrypts the URL and makes it available on the site. When it's passed through the URL, page 2 decrypts the URL and downloads…
Mitch
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Is there any difference between AES_128_CBC and AES_128_CBC_SHA algorithm?

Is there any difference between AES_128_CBC and AES_128_CBC_SHA algorithm? I have a client document which says AES_128_CBC_SHA algorithm for data encryption. could anybody can share some Library files (.net, C,C#) which does AES_128_CBC_SHA…
Jijith
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