A set of PHP reversible encryption and decryption algorithm instance code _ PHP Tutorial

A set of PHP reversible encryption and decryption algorithm instance code. 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 encryption of most passwords that need to be restored, 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.

Bytes. This can effectively prevent data leaks, but these methods only apply to data encryption that does not require restoration. To restore...