# Summary of definitions and usage of md5 () functions in php

Source: Internet
Author: User
Tags crypt md5 hash
PHP encryption function-md5 () function encryption what is MD5 () function? MD5 () function is the MD5 hash value of the calculator string, using MD5 algorithm, the full name of MD5 is Message-DigestAlgorithm5, it is used to calculate data information of different lengths into a 128-bit value through a series of algorithms, which is to convert a byte string of any length into a large integer of a certain length. Note that this is a "byte string" instead of a "string", because this conversion is only related to the value of the byte, and is related to the character set or encoding... PHP encryption function-md5 () function encryption what is MD5 () function? The MD5 () function is the MD5 hash value of the calculator string. it uses the MD5 Algorithm. The full name of MD5 is Message-Digest Algorithm 5, it is used to calculate data information of different lengths into a 128-bit value through a series of algorithms, which is to convert a byte string of any length into a large integer of a certain length. Note that this is a "byte string" instead of a "string", because this conversion is only related to the value of the byte and has nothing to do with the character set or encoding method. In the previous section, we introduced the encryption function of the PHP encryption function-crypt () function. I believe you have some knowledge about the encryption function of PHP. today, we will introduce in detail the encryption function of the PHP-md5 () function. First, let's take a look at the syntax structure of the MD5 () function: string md5 (string str [, bool raw_output]); where, the string str is the plaintext to be encrypted, and the rew_output parameter

1. PHP encryption function-md5 () function-encryption instance usage

Introduction: The MD5 () function is the MD5 hash value of the calculator string. it uses the MD5 Algorithm. The full name of MD5 is Message-Digest Algorithm 5, it is used to calculate data information of different lengths into a 128-bit value through a series of algorithms, which is to convert a byte string of any length into a large integer of a certain length. Note that this is a "byte string" instead of a "string", because this conversion is only related to the value of the byte and has nothing to do with the character set or encoding method.

2. php object-oriented issues

Introduction: {code...} my question is: why does the md5 () function Report an error when it is used as shown above ?? In php object-oriented attributes, cannot php built-in methods be used ???

3. Introduction to the md5, crypt, and base64_encode encryption functions of vbscript. encode php

Introduction: vbscript. encode: vbscript. use of encryption functions such as md5, crypt, and base64_encode in encode php: irreversible encryption functions: md5 () and crypt () md5 () are used to calculate MD5. The syntax is: string md5 (string str); crypt () encrypts the string with the standard DES module of UNIX. This is a one-way encryption function and cannot be decrypted. To compare the string, place the first two characters of the encrypted string in the salt parameter, and then compare the encrypted string. Syntax: string cry

4. PHP encryption technology

Introduction: PHP encryption technology: I learned some knowledge about PHP encryption a few days ago. now I will summarize several encryption forms in PHP: Md5 () encryption algorithm Crypt () encryption algorithm Sha1 () encryption Algorithm URL encoding encryption technology Base64 encoding encryption technology Md5 () encryption algorithm syntax: string md5 (string \$ str [, bool \$ raw_output = false]) \$ str: optional original string (not commonly used)

5. Introduction to the md5, crypt, and base64_encode encryption functions of php _ PHP Tutorial

Introduction: Use of php encryption functions such as md5, crypt, and base64_encode. Irreversible encryption functions: md5 () and crypt () md5 () are used to calculate MD5. The syntax is: string md5 (string str); crypt () encrypts the string with the standard DES module of UNIX. This is

6. PHP5.3 language feature _ PHP Tutorial

Introduction: PHP5.3 language features. Performance improvement php 5.3 Overall performance improvement 5-15% md5 () faster 10-15% Better stack implementation in the engine Constants move to read-only memory exception handling process improvement (simplified,

7. php function note_php tutorial

Introduction: php function notes. String function: round () md5 () number_format () preg_match () trim () printf () str_replace () strip_tags () explode () implode () sprintf strpos strrchr strrpos strstr substr

8. php md5 encryption functions-PHP Tutorial

Introduction: php md5 encryption function for details. Many php developers will use this md () encryption function, but some of them may not know it. let's take a look at the md5 () function parameters today. syntax md5 (string, raw) md5 () function

9. php custom encryption solution code _ PHP Tutorial

Introduction: php custom encryption solution implementation code. The Mcrypt encryption library in PHP requires additional settings. many people directly use the md5 () function for encryption. this method is indeed safe, but because md5 is irreversible encryption, the password cannot be restored.

10. several common encryption functions of PHP, common encryption functions of PHP _ PHP Tutorial

Brief introduction: several common encryption functions in PHP and common encryption functions in PHP. Several common encryption functions in PHP. MD5 encryption for common PHP encryption functions: string md5 (string \$ str [, bool \$ raw_output = false]) 1. md5 () is a 32-character hexadecimal number by default.

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The above is the definition and usage of the md5 () function in php. For more information, see other related articles in the first PHP community!

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