Summary of PHP encryption methods

There are 4 ways to encrypt PHP, in addition to the encryption and decryption of URLs. Hope can be useful for your development.

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Note Link: Http://pan.baidu.com/s/1qYdQdKK Password: pvj2

First, MD5 () encryption technology
Grammar:

String MD5 (string $str [, bool $raw _output=false]): Calculates the MD5 hash value of STR

$STR: Raw String

$raw _output: If the optional raw_output is set to true, then the MD5 digest will be returned in the original binary format of 16 bytes in length. Returns the hash value returned as a 32-character hexadecimal number.

Note: The MD5 is irreversible, so it can only force decoding. This means that after encryption, the password cannot be parsed by other functions, only the corresponding original characters can be resolved by the 32-bit characters of the third-party matching database.

　　Decrypt website: http://www.cmd5.com/

Instance:

<?phpheader ("content-type:text/html;charset= ' UTF8 '"); Set the encoding echo MD5 ("DFA");//1b014086a5cf92eb3238d0d45c8c61a4echo "<br>"; Echo MD5 ("DFA", $raw _output=true); Output: @???? 28?? \?a?5owv6k++572rlwtpbg== $STR =1;echo MD5 (MD5 ($STR)); Can be encrypted multiple times if ($STR) {echo "Registration successful, 3 seconds after the jump to the login page"; echo "<meta http-equiv= ' refresh ' content= ' 3;url=login.html '/>"; 3 seconds after the page is refreshed, and then jump to Login.html}else{echo "registration failed, please re-register"; echo "<meta http-equiv= ' refresh ' content= ' 1;url=reg.html '/ > ";}? >

　　

Second, crypt encryption algorithm
Grammar:
String crypt (String $str [, String $salt]);
Returns a hash string based on the standard Unix des algorithm or other available alternative algorithms on the system.
$STR: Confidential plaintext required
$salt: Encrypt the interference string, make the encoding more secure

Attention:
If the $salt parameter is not added to the encryption, a disturbance string is randomly generated, otherwise the encryption text will be refreshed.

Instance:

<?phpecho crypt ("Imooc"), echo "
　　
Three, SHA1 () encryption algorithm
Grammar:
String SHA1 (String $str [, bool $raw _output=false]): Computes the SHA1 hash value of a string
$STR: Encrypted string
$raw _output: If the optional raw_output parameter is set to True, the SHA1 digest is returned in the original format of 20-character length, otherwise the return value is a 40-character hexadecimal number.
Returns a SHA1 hash value string.
Instance:
<?phpecho SHA1 ("LEOHC"); echo "
　　
Four, URL encoding encryption technology
　　1.urlencode (String $str): encoded URL string
$STR: The string to encode
Return value: Returns the encoded string
　　2.urldecode (String $str): Decodes the encoded URL string.
$STR: the string to decode
Return value: Returns the decoded string
Encoding specification: All non-alphanumeric characters except-_ in this string are replaced with a percent sign (%) followed by a two-digit hexadecimal number, and a space is encoded as a plus (+)
　　3.rawurlencode (String $str): Encode URLs by RFC1738
$STR: The URL to encode
Return value: Return string, encode space as%20
　　4.rawurldecode (String $str): Decodes an encoded URL string
$STR: the URL to decode
Return value: Returns a string in which the percent percent in this string followed by a two-bit hexadecimal sequence is replaced with the literal character
Instance:
<?php/* source code conversion code? %3f=%3d space +%%25&%26\%5c*/$str = "h e l lo World"; Echo UrlEncode ($STR); echo "
　　
Five, BASE64 information coding encryption Technology
　　1.base64_encode (String $data): Encode data using base64
$data: The data to encode
　　2.base64_decode (String $data [, bool $strict =false]): Decodes data encoded with MIME base64
$strict: Returns False if the input data exceeds the Base64 alphabet;

Instance:
<?php$data= "-kin", Echo Base64_encode ($data), echo "
　　
Vi. Classification and summary of Information encryption technology
Information encryption:
　　1. Single Hash Encryption
Single Hash Encryption technology introduction:
One-way hash encryption refers to the calculation of the length of a fixed-length output by hashing the information of different input lengths, and the hash calculation process is unidirectional, that is, the output of fixed length cannot be computed and the input information is obtained.
Salt
↓
PlainText-----> One-way hashing algorithm--Ciphertext--->
2. Symmetric hashing encryption
Symmetric encryption Technology Introduction:
When you heap encryption, the keys used for encryption and decryption are the same key or can be extrapolated to each other.
Salt key
↓↓
PlainText-----> Encryption algorithm--Ciphertext---> Decryption algorithm----clear
3. Asymmetric Hash Encryption
Asymmetric encryption and decryption use a key that is not the same key, one of which is public, called the public key, and the other is known only by the owner.
Encryption Key Decryption key
↓↓
PlainText-----> Encryption algorithm--Ciphertext---> Decryption algorithm----clear
Hope to be helpful during the development process.
attached  Note Link: Http://pan.baidu.com/s/1qYdQdKK Password: pvj2
Summary of PHP encryption methods