symmetric encryption example

I. What is symmetry?Algorithm? Symmetric algorithms are also called single-key algorithms, that is, encryption keys can be derived from decryption keys. Likewise, decryption keys can also be derived from encryption keys. To put it bluntly, the encryption key and decryption key are the same key. The security of the

. This section briefly introduces symmetric encryption. Now let's look at asymmetric encryption. Figure 9-2 is an asymmetric encryption: Figure 9-2 asymmetric algorithms In asymmetric algorithms, you must first have a key pair, which contains two parts: the Public Key (PK) and the private key (SK). The public key is u

The last blog about how to play the hash algorithm, but that article did not explain clearly. This blog post I will try to make the things that are not explained clearly. Of course, the theme of this article is to play symmetric encryption. . NET of symmetric encryption technology There are mainly such several: Des,ae

Simple symmetric encryption algorithm implementation in php and php Encryption Algorithm Preface I found a good symmetric encryption algorithm for PHP on the Internet. In the PHP syntax environment, there are symmetric algorithms

Asymmetric encryption algorithm is relative to symmetric encryption algorithm, for symmetric encryption algorithm please refer to the previous summary, today for everyone to introduce the DH algorithm, DH is a key exchange algorithm, the receiver based on the sender

{ new Secretkeyspec (Base64util.decode (key), algorithm); return secretkey; } PbePbe and DES, AES are symmetric encryption, the difference is that the key can be managed by the user, that is, the key can not be generated through the keygenerator, can be any character. In order to enhance security, PBE mandatory must have parameters (Java.security.spec.AlgorithmParameterSpec), can be un

(InvalidKeyException e) {throw new RuntimeException (e);catch (Illegalblocksizeexception e) {throw new RuntimeException (e);catch (Badpaddingexception e) {throw new RuntimeException (e);}}/*** Decryption of data by incoming RSA ciphertext and private key* * * * */public static string Rsadeencoding (String Sec,privatekey privkey) {try {Cipher CIP = cipher.getinstance ("RSA");Cip.init (CIP. Decrypt_mode, Privkey);byte[] by = Base64decoderstream.decode (Sec.getbytes ());Return a new String (cip.do

One, the ideaSymmetric encryption contains a thing known as a key, before the message is sent using a key to encrypt the message, get ciphertext and send, the receiver receives the ciphertext, using the same key to decrypt, to obtain the original message.PS : The process of encrypting a message with a key, which is done by a cryptographic algorithm, is usually public. Two, the process of symmetric encryptio

Original address: http://www.moye.me/2015/06/14/cryptography_rsa/IntroductionFor the addition and decryption, I have been in a knowledge of its reason why the state, the core part of the project does not rely on encryption and decryption algorithm, can reluctantly deal with the past, once the need for frequent applications such as AES/RSA algorithm, this state is quite a catch.It's time to get to know the principle, so I found this graphic cipher tech

For the addition and decryption, I have been in a knowledge of its reason why the state, the core part of the project does not rely on encryption and decryption algorithm, can reluctantly deal with the past, once the need for frequent applications such as AES/RSA algorithm, this state is quite a catch.It 's time to get to know the principle, so I found this one . Graphic cipher Technology Give yourself a supplementary lesson:In the book in the light o

This blog post lists the. NET under the common symmetric encryption algorithm, and they are made into small demo, hope to be helpful to everyone. Common code Static byte[] CreateKey (int num) { byte[] result = new Byte[num]; Random rand = new Random (); for (int i = 0; i Des Calling code Des symmetric

From: http://snowolf.iteye.com/blog/380034 Next, we will introduce symmetric encryption algorithms. The most common is des data encryption algorithms.Des Des-Data Encryption Standard, which is the data encryption algorithm. It was published by IBM in 1975. The DES algorithm

What is symmetric encryption technology? Symmetric encryption uses symmetric encryption technology, which features that file encryption and decryption use the same key, that is, the

Symmetric encryption, decryption, encryption and decryption ///

This is a creation in Article, where the information may have evolved or changed. Symmetric encryption algorithms, that is, encryption and decryption using the same cryptographic key encryption and decryption algorithm. Block cipher is a class of encryption an

Package COM. jadyer. util. codec; import Java. security. key; import Java. security. nosuchalgorithmexception; import javax. crypto. cipher; import javax. crypto. keygenerator; import javax. crypto. secretkey; import javax. crypto. secretkeyfactory; import javax. crypto. spec. desedekeyspec; import Org. apache. commons. codec. binary. base64;/*** desede symmetric encryption algorithm * @ see desede, also kn

(+, new SecurerandoM (Password.getbytes ())); Secretkey Secretkey = Kgen.generatekey (); byte[] Encodeformat = secretkey.getencoded (); Secretkeyspec key = new Secretkeyspec (Encodeformat, AES);//Cipher The object actually completes the cryptographic operation cipher cipher = Cipher.getinstance (AES);// Initialize the Cipher object with a key Cipher.init (Cipher.decrypt_mode, key);//formally perform decryption operation byte[] result = cipher.dofinal (content); return result ;} catch (NoSuchAlg

, Allencrypt, 0, keyiv.length); Buffer.blockcopy (cipherbytes, 0, Allencrypt, keyiv.length * sizeof (BYTE), cipherbytes.length); Return Convert.tobaSe64string (Allencrypt);} public static string Decrypt (String showtext, String aeskey) {string result = string. Empty; try {byte[] ciphertext = convert.frombase64string (Showtext); int length = Ciphertext.length; SymmetricAlgorithm rijndaelcipher = Rijndael.create (); Rijndaelcipher.key = convert.frombase64string (A

DES (Data Encryption Standard) is a group symmetric cipher algorithm . des employs a 64-bit packet length and a 56-bit key length , which takes 64-bit inputs through a series of transformations to get 64-bit output. Decryption uses the same steps and the same key. The key length of DES is 64 bits due to the n*8 (n=1,2,... 8) is the parity bit, so the actual participation in the

Remember before the test soft test and recent exams, always appear the problem of encryption algorithm, summed up here.Summary of symmetric and asymmetric and reversible non-reversible cryptographic algorithms:According to the different key types, modern cryptography can be divided into two types: symmetric encryption