PHP reversible encryption and decryption algorithm program code _ PHP Tutorial

PHP reversible encryption and decryption algorithm program code. Our commonly used md5 algorithm is irreversible theoretically, but there is a powerful way to calculate the md5 algorithm, but it only takes time based on the complexity, however, sometimes our common md5 algorithms are irreversible in theory, but there is a powerful way to calculate the md5, but the time needed for complexity is different, but sometimes we want our data to be encrypted and transmitted before it can be decrypted. I will provide you with a function.

For most password encryption, we can use md5, sha1, and other methods. This can effectively prevent data leaks, but these methods only apply to data encryption that does not require restoration.

For information to be restored, a reversible encryption and decryption algorithm is required.

The following PHP functions implement encryption and decryption:

The encryption algorithm is as follows:

The code is as follows:
Function encrypt ($ data, $ key) { $ Key = md5 ($ key ); $ X = 0; $ Len = strlen ($ data ); $ L = strlen ($ key ); For ($ I = 0; $ I <$ len; $ I ++) { If ($ x = $ l) { $ X = 0; } $ Char. = $ key {$ x }; $ X ++; } For ($ I = 0; $ I <$ len; $ I ++) { $ Str. = chr (ord ($ data {$ I}) + (ord ($ char {$ I}) % 256 ); } Return base64_encode ($ str ); }

The decryption algorithm is as follows:

The code is as follows:

Function decrypt ($ data, $ key) { $ Key = md5 ($ key ); $ X = 0; $ Data = base64_decode ($ data ); $ Len = strlen ($ data ); $ L = strlen ($ key ); For ($ I = 0; $ I <$ len; $ I ++) { If ($ x = $ l) { $ X = 0; } $ Char. = substr ($ key, $ x, 1 ); $ X ++; } For ($ I = 0; $ I <$ len; $ I ++) { If (ord (substr ($ data, $ I, 1) <ord (substr ($ char, $ I, 1 ))) { $ Str. = chr (ord (substr ($ data, $ I, 1) + 256)-ord (substr ($ char, $ I, 1 ))); } Else { $ Str. = chr (ord (substr ($ data, $ I, 1)-ord (substr ($ char, $ I, 1 ))); } } Return $ str; }

An encryption key ($ key) is required for the above encryption and decryption process ).

The code is as follows:
$ Data = 'php encryption and decryption algorithmic '; // encrypted information $ Key = '000000'; // key $ Encrypt = encrypt ($ data, $ key ); $ Decrypt = decrypt ($ encrypt, $ key ); Echo $ encrypt, "n", $ decrypt;

The output is similar to the following:

GniCSOzZG + HnS9zcFea7SefNGhXF
PHP encryption and decryption algorithm

From the above results, we can see that this is a set of reversible encryption and decryption algorithms that can be used to encrypt part of the data to be restored.

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