MD5 or HASH value is an irreversible algorithm. If you need to restore the ciphertext to plain text, symmetric and asymmetric reversible algorithms are required.
First, we will briefly introduce these two types of algorithms. Figure 9-1 is a symmetric algorithm:
Figure 9-1 symmetr
Original article, welcome to forward the circle of friends, reproduced please indicate the sourceCryptography is a very well-known addition and decryption library in the Python language, providing a high level of abstraction at the algorithm level, very simple, intuitive, and pythonic, while preserving the low-level interfaces of various algorithms, preserving flexibility.We know that encryption is generall
Chapter 2 asymmetric encryption algorithms-DH and asymmetric encryption algorithms-dh
Note: In this section, refer to "advanced encryption algorithms-asymmetric encryption
authentication-digital certificate Hackers can replace your public key, and then use his private key to do a digital signature to send you messages, and you use the hacker forged public key can be successfully verified, you will mistakenly think the source has not changed. In this case, the CA (Certificate Center Certificate Authority) is required to authenticate the public key. The certificate center uses its own private key to encrypt the public key of the sender of the message along with som
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
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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
1. symmetric encryption Algorithm 1.1 definition raw data Span style= "font-family: the song Body;" >) and encryption key Span style= "font-family: the song Body;" > (mi yue key and the inverse algorithm of the same algorithm to decrypt the ciphertext, so that it can be restored to readable plaintext. In symmetric
with key 11110011 as follows:
01010111 01101001 01101011 01101001
11110011 11110011 11110011 11110011
=
10100100 10011010 10011000 10011010
This method of encryption is similar to symmetric encryption
:
01010111 01101001 01101011 01101001
11110011 11110011 11110011 11110011
=
10100100 10011010 10011000 10011010
This method of encryption is similar to symmetric encryption, so the way to decrypt it is as follows:
algorithmsThe commonly used symmetric encryption algorithms are as follows:AES-GCM is a commonly used packet encryption algorithm, but its disadvantage is that the computational amount is large, resulting in higher performance and power overhead. To address this issue, Intel has introduced a x86 instruction extension
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
Symmetric encryption algorithmTip: Encrypted content belongs to the topic of advanced programmers! Some content will be very dull! Attention to grasp the idea of encryption and operation steps can be! Code does not require to write, as long as it will be used on the line!
Also known as the traditional encryption
Recently, it was a whim to save some confidential things to the database, and then I thought about how to make others even if they enter the database and do not understand what the storage is, so there is only encryption; but we have to look at it ourselves. we can only find some symmetric encryption algorithms. we can
, sends the ciphertext to the receiver, and the receiver decrypts the ciphertext with this key to get the original text. Since the usual encryption algorithms are public, the key to the original encryption is the key. For this kind of encryption and decryption using the same key algorithm, we call
=myserviceprovider.createencryptor (New byte[]{100,110,120,130,100,110,120,130},new byte[]{100,110,120,130,100,110,120,130});
The purpose of the CryptoStream object is to linger the data into the stream of the encrypted transformation
CryptoStream mycryptostream=new CryptoStream (fs,mytransform,cryptostreammode.write);
Writes data from a byte array to the encrypted stream
Mycryptostream.write (yourinputstorage,0,yourinputstorage.length);
Turn off the encrypted stream object
Mycryptostream.close
Comments: Secret-Key or Symmetric-Key Cryptography (Secret-Key or Symmetric Ric-Key Cryptography) is a network technology security technology that ensures information disclosure by restricted parties with decryption keys. In the key encryption mode, you only need to provide one key for encryption and decryption. It is
first, symmetric encryption
Symmetric encryption, is a more traditional encryption method, its cryptographic operations, decryption operations using the same key, the sender of information and the recipient of information in the transmission and processing of information,
using the encryption method of single-key cryptosystem, the same key can be used as the encryption and decryption of information, which is called symmetric encryption, also known as single-key encryption. encryption
Symmetric encryption algorithm is an early application of encryption algorithm, the technology is mature. In the symmetric encryption algorithm, the sender of the data sends the plaintext (raw data) and the encryption key (Mi Yao)
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