des

Does anyone have any examples of how to encrypt serialized data to a file and then read it back using DES? I've written some code already that isn't working, but I'd rather see a fresh attempt instead of pursuing my code. EDIT : Sorry, forgot to mention I need an example using XmlSerializer.Serialize/Deserialize. Bryce Kahle Encryption public static void EncryptAndSerialize(string filename, MyObject obj, SymmetricAlgorithm key) { using(FileStream fs = File.Open(filename, FileMode.Create)) { using(CryptoStream cs = new CryptoStream(fs, key.CreateEncryptor(), CryptoStreamMode.Write)) {

# -*- coding=utf-8-*- from Crypto.Cipher import DES import base64 """ des cbc加密算法 padding : PKCS5 """ class DESUtil: __BLOCK_SIZE_8 = BLOCK_SIZE_8 = DES.block_size __IV = "\0\0\0\0\0\0\0\0" # __IV = chr(0)*8 @staticmethod def encryt(str, key): cipher = DES.new(key, DES.MODE_CBC, DESUtil.__IV) x = DESUtil.__BLOCK_SIZE_8 - (len(str) % DESUtil.__BLOCK_SIZE_8) if x != 0: str = str + chr(x)*x msg = cipher.encrypt(str) # msg = base64.urlsafe_b64encode(msg).replace('=', '') msg = base64.b64encode(msg) return msg @staticmethod def decrypt(enStr, key): cipher = DES.new(key, DES.MODE_CBC,DESUtil.__IV) #

I'm trying to authenticate DESFire card with my android application. I use the example in this link to decypher the bytes I got from the card. For that, I ruled out padding in decryption (commented out below), because DESFire documentation points it out. Also, if I don't do so, decryption returns 7 bytes for input of 8 bytes. Below are DES and TripleDES decryption functions I use: public static byte[] TripleDES_Decrypt(byte[] data,byte[][] keys) { int i; byte[] tmp = new byte[data.length]; byte[] bloc = new byte[8]; K = generateSubKeys(keys[0]); K1 = generateSubKeys(keys[1]); K2 =

3DES 一、简介 3DES就是为了加强DES的安全性，对数据进行3次DES操作 二、加密三要素 明文、密文 算法 加密（加->解->加，目的是为了兼容DES） DES加密 DES解密 DES加密 解密 DES解密 DES加密 DES解密 密钥 注意3把密钥不能使用一样，否则加密过程中第1次加密和第2次解密操作就会相互抵消相当于只进行了一次DES加密 三把DES密钥，每个7字节密钥+1字节错误检测，总共24字节 三、备注 安全性达标，但性能比较低不推荐使用 来源： https://blog.csdn.net/YIMT_F/article/details/100064390

I have two method for Encrypt-save and decrypt-load Object from file in Android Internal Storage. Encrypt and save process is done without any problem, but when I want to load the object StreamCorruptedException occurs in inputStream = new ObjectInputStream(cipherInputStream); I searched SO more and more but I did't find a solution for my problem. all other solutions are for socket life or like this. my code is below: private static byte[] iv = { (byte) 0xB1, (byte) 0x15, (byte) 0xB5, (byte) 0xB7, (byte) 0x66, (byte) 0x43, (byte) 0x2F, (byte) 0xA4, (byte) 0xB1, (byte) 0x15, (byte) 0x35, (byte)

I've written a DES implementation as an exercice and am now wondering if and where (triple-)DES is used today. I've read about banking cards using it, but I can't find any reliable source for it. Triple-DES is still in use today but is widely considered a legacy encryption algorithm. DES is inherently insecure, while Triple-DES has much better security characteristics but is still considered problematic. NIST is the government organization that standardizes on cryptographic algorithms. The most current symmetric-key encryption algorithm NIST standard is AES, the Advanced Encryption Standard.

对称加密：双方使用的同一个密钥，既可以加密又可以解密，这种加密方法称为对称加密，也称为单密钥加密。 优点： 速度快，对称性加密通常在消息发送方需要加密大量数据时使用，算法公开、计算量小、加密速度快、加密效率高。 缺点： 在数据传送前，发送方和接收方必须商定好秘钥，然后 使双方都能保存好秘钥。其次如果一方的秘钥被泄露，那么加密信息也就不安全了。另外，每对用户每次使用对称加密算法时，都需要使用其他人不知道的唯一秘 钥，这会使得收、发双方所拥有的钥匙数量巨大，密钥管理成为双方的负担。 在对称加密算法中常用的算法有：DES、AES等。 AES：密钥的长度可以为128、192和256位，也就是16个字节、24个字节和32个字节 DES：密钥的长度64位，8个字节。 非对称加密：一对密钥由公钥和私钥组成（可以使用很多对密钥）。私钥解密公钥加密数据，公钥解密私钥加密数据（私钥公钥可以互相加密解密）。 私钥只能由一方保管，不能外泄。公钥可以交给任何请求方。 在非对称加密算法中常用的算法有： RSA、Elgamal、背包算法、Rabin、Diffie-Hellman、ECC（椭圆曲线加密算法）。 使用最广泛的是RSA算法，Elgamal是另一种常用的非对称加密算法。 缺点： 速度较慢 优点： 安全 1.分类 加密算法首先分为两种：单向加密、双向加密。 单向加密是不可逆的，也就是只能加密，不能解密