encryption

问题 Is there exist a ciphering approach such that encrypting and decrypting order is arbitrary? Like using two padlocks on the same lock loop. That is, if there are two keys (or keypairs) K1, K2 , message M , and the cryptogram C is obtained as (for example) C=M*K1*K2 (where * denotes ciphering), then the message M can be retrieved in each of the following ways: 1) M=C*K1*K2 , 2) M=C*K2*K1 (here * denotes deciphering). Obviously, XOR is a trivial candidate. Do any cryptographically strong

问题 I am learning Rails, at the moment, but the answer doesn't have to be Rails specific. So, as I understand it, a secure password system works like this: User creates password System encrypts password with an encryption algorithm (say SHA2). Store hash of encrypted password in database. Upon login attempt: User tries to login System creates hash of attempt with same encryption algorithm System compares hash of attempt with hash of password in the database. If match, they get let in. If not,

问题 I've got a project and a part of it is incorporating encryption into a FAT file system. The goal of the project is not the encryption, so I'm free to use open-source pre-done libraries. Ideally what I'm after is a C library which uses RSA, that already has the methods for computing keys and encrypting/decrypting files. 回答1: You might want to check out NaCl (pronounced as "salt"), especially since this is for an embedded system. It has CPU-specific tunings and doesn't require any dynamic

问题 I want to generate SHA512 hashed passwords for inclusion directly into a /etc/shadow file for use with chef's user resource. Normally I'd go to the stdlib's Digest library for this, but it doesn't generate the hash in the right format: ruby-1.9.2-p136 :001 > require 'digest/sha2' => true ruby-1.9.2-p136 :002 > Digest::SHA512.hexdigest('test') => "ee26b0dd4af7e749aa1a8ee3c10ae9923f618980772e473f8819a5d4940e0db27ac185f8a0e1d5f84f88bc887fd67b143732c304cc5fa9ad8e6f57f50028a8ff" The format that

问题 This is the scenario we have: We have huge encrypted files, in the order of gigabytes that we can decrypt correctly if we read them until the end. The problem arises when we are reading and detect some flag in the file, then we stop reading and call reader.Close(), what happens is that a CryptographicException: "Padding is invalid and cannot be removed." is thrown. I have this small console app that reproduce this behavior, to test it just run it, it will create a file in your C:\ drive and

问题 This is the scenario we have: We have huge encrypted files, in the order of gigabytes that we can decrypt correctly if we read them until the end. The problem arises when we are reading and detect some flag in the file, then we stop reading and call reader.Close(), what happens is that a CryptographicException: "Padding is invalid and cannot be removed." is thrown. I have this small console app that reproduce this behavior, to test it just run it, it will create a file in your C:\ drive and

问题 ionCube stores php files in encrypted format and it is installed as php extension but what i want to know is when I request the encrypted php file from non-encrypted php file how does php compiler executes it. Does it send the encrypted file to ionCube server and get the original file and compile that or there is something else. Means how the communication is going on between our server and ionCube. I guess it is through curl but i want to know how it works. 回答1: As you may have picked up on

问题 In my Android app I am communicating with a web service the data sent and responded are encrypted with AES encryption. So what I do is the following. I'm sending a base64 encoded AES encrypted JSON String to share.php Share.php will then decrypt this string and insert it into the database. After that the PHP will encrypt en encode the response. My Android application then needs to decode en decrypt this message. But the decryption of the PHP response is not going very well. This is my AES

问题 I have a Linux server running a Java-jar file that encrypts several files. The Android and iPhone App download that file and shall decrypt it. What algorithm I have to use to do so? I recognized that the algorithms I used in Java do not work in Android. What I did in Java was: private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception { SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES"); Cipher cipher = Cipher.getInstance("AES"); cipher.init(Cipher.ENCRYPT_MODE, skeySpec);

问题 I have a Linux server running a Java-jar file that encrypts several files. The Android and iPhone App download that file and shall decrypt it. What algorithm I have to use to do so? I recognized that the algorithms I used in Java do not work in Android. What I did in Java was: private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception { SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES"); Cipher cipher = Cipher.getInstance("AES"); cipher.init(Cipher.ENCRYPT_MODE, skeySpec);