cryptography

问题 I'm learning about RSA encryption and I have understood how to encrypt a single letter. I have problems understanding how does RSA work while encrypting a sentence. For eg: Single letter encryption: A Encryption= A^e (mod n) But in a sentence. For eg: Sentence encryption: Hello World Does each word get encrypted or does the sentences as a whole get encrypted? 回答1: Neither. In practice RSA is almost always coupled with a symmetric cipher such as AES to encrypt larger ciphertext. RSA in itself

问题 This question already has answers here : SecureRandom provider “Crypto” unavailable in Android N for deterministially generating a key (3 answers) Closed 3 years ago . Seems like "Crypto" provider has been removed in Android N. My application crashing because of NoSuchProviderException. If I change the provider and Algorithm then it will affect user who are all using the app currently. Any one have a idea? KeyGenerator kGen = KeyGenerator.getInstance(KEY_GENERATOR_ALGORITHM); SecureRandom sr

问题 Imagine that a server is serving public keys of the users to their partners to make encrypted communication possible. However, the server does NOT have access to the private keys.. Anyway - imagine the server is hacked and it sends not the requested public keys: Alice requests Bob's public key Server sends Eve's public key Bob requests Alice's public key Server sends Eve's public key Alice sends a message to Bob Server unpacks message, reads it and repacks it -> sends to Bob... Bob sends a

问题 Can you anybody explain me a difference between creating HmacSha512 signature using Crypto module of Node.JS and Google Apps Script? Code 1 - Node.JS var secret = "my secret"; var message = "message"; var crypto = require("crypto"); var hmac = new crypto.createHmac("sha512", secret); var signature = hmac.update(message).digest("base64"); console.log(signature); Code 1 - Google Apps Script var secret = "my secret"; var message = "message"; var signature = Utilities.base64Encode(Utilities

问题 I was attempting to generate a public ECDSA key from a private key, and I haven't managed to find much help on the internet as to how to do this. Pretty much everything is for generating a public key from a public key spec, and I don't know how to get that. So far, this is what I've put together: public void setPublic() throws GeneralSecurityException { ECNamedCurveParameterSpec params = ECNamedCurveTable.getParameterSpec("secp256k1"); KeyFactory fact = KeyFactory.getInstance("ECDSA", "BC");

问题 In order to write an simple nodejs app talking to an server written in java I have to implement the following functionality for nodejs. public class Crypto { Cipher decipher; byte[] salt = { (byte) 0x01, (byte) 0x02, (byte) 0x03, (byte) 0x04, (byte) 0x0A, (byte) 0x0B, (byte) 0x0C, (byte) 0x0D }; int iterationCount = 10; public Crypto(String pass) { try { KeySpec keySpec = new PBEKeySpec(pass.toCharArray(), salt, iterationCount); SecretKey key = SecretKeyFactory.getInstance(

问题 I need to decrypt some data that I receive from the server, and the programmer who made the API directed me to this Encrypter class, to see what he used to encrypt. Now based on that class, I found that the algorithm used is AES128 CBC, and that the string I receive is Base64 encoded and contains other data, not just the ciphertext. Namely that if I receive the following String:

问题 I'm trying to implement HOTP (rfc-4226) in Golang and I'm struggling to generate a valid HOTP. I can generate it in java but for some reason my implementation in Golang is different. Here are the samples: public static String constructOTP(final Long counter, final String key) throws NoSuchAlgorithmException, DecoderException, InvalidKeyException { final Mac mac = Mac.getInstance("HmacSHA512"); final byte[] binaryKey = Hex.decodeHex(key.toCharArray()); mac.init(new SecretKeySpec(binaryKey,

问题 So my question for you stackoverflow geniuses is: if there a way (native, library, framework, whatever..) to encrypt data with AES (preferably 128 but could be 256 too) using a strong Authenticated encryption algorithm , let's say GCM mode ? Question is short, I have done some research and I only found one library that seems to support it ( RNCryptor ) but it also seems to use password to crypt instead of keys (like you provide a password and the library made the key) and I don't like that a

问题 I'm stuck with the crypto api because I know little about cryptography. I have this XML: <RSAKeyValue> <Modulus>1znidPBIcMcO7K/53tkTSyKqxlG5Mcws8kVtijS4tyEU4W/FEVWYpOtv+Stnb4Vt</Modulus> <Exponent>AQAB</Exponent> </RSAKeyValue> Signature: rNbdUP-p4pEGfwQSwR6VPvAVZ-sZu-ptgw8SofYYmNTlfUB9iUbb593eCAuT5jsqDTC Original data: <xml>...some big xml...</xml> I want to verify the signature, how do I do that? (I'm using node v0.10.18) 回答1: I'm not really a node.js dev, so this is super hacky.. Here's a