Example of php custom encryption function and decryption

Encryption is the process of converting some characters into another string. Simply put, it is to lock the door and only you have the enabled key. As a programmer, you should have your own encryption method. Currently, the most popular encryption algorithm is the MD5 () encryption method. However, it is not safe to use software that has been cracked on the website. The following describes the custom encryption functions.

The code is as follows:

Copy code

"/* Encryption */ Function addcoder ($ str)     { $ Yuan = 'Aba! C1dB # ef2 @ Cg $ h % iD_3jkl ^ E: m} 4n. o {& F * p) 5q (G-r [sH] 6tuIv7w + jxy8z9k0 '; $ Jia = 'Zay % 0Bx + 1C $ wDv ^ Eu2-t3 (F {sr & G4q_pH5 * on6I) m: l7.Jk] j8K} ih @ gf9 # ed! Cb ['; If (strlen ($ str) = 0) return false; For ($ I = 0; $ I <strlen ($ str); $ I ++)         { For ($ j = 0; $ j <strlen ($ yuan); $ j ++) { If ($ str [$ I] ==$ yuan [$ j])                     { $ Results. = $ jia [$ j]; Break; }             }         } Return $ results;     }   /* Decrypt */ Function removecoder ($ str) { $ Yuan = 'Aba! C1dB # ef2 @ Cg $ h % iD_3jkl ^ E: m} 4n. o {& F * p) 5q (G-r [sH] 6tuIv7w + jxy8z9k0 '; $ Jia = 'Zay % 0Bx + 1C $ wDv ^ Eu2-t3 (F {sr & G4q_pH5 * on6I) m: l7.Jk] j8K} ih @ gf9 # ed! Cb ['; If (strlen ($ str) = 0) return false; For ($ I = 0; $ I <strlen ($ str); $ I ++) { For ($ j = 0; $ j <strlen ($ jia); $ j ++)   { If ($ str [$ I] ==$ jia [$ j]) { $ Results. = $ yuan [$ j]; Break; }   } } Return $ results;     } $ Str = "www.111cn.net "; Echo "before encryption:". $ str. "<br> "; $ Str1 = addcoder ($ str ); Echo "encrypted:". $ str1. "<br> "; $ Str2 = removecoder ($ str1 ); Echo "decrypted:". $ str2. "<br> ";

Example 2: Use md5 + base64_encode for editing.

The code is as follows:

Copy code

<? Php // Www.111cn.net Function passport_encrypt ($ txt, $ key ){ Srand (double) microtime () * 1000000 ); $ Encrypt_key = md5 (rand (0, 32000 )); $ Ctr = 0; $ Tmp = ''; For ($ I = 0; $ I <strlen ($ txt); $ I ++ ){ $ Ctr = strlen ($ encrypt_key )? 0: $ ctr; $ Tmp. = $ encrypt_key [$ ctr]. ($ txt [$ I] ^ $ encrypt_key [$ ctr ++]); } Return base64_encode (passport_key ($ tmp, $ key )); } Function passport_decrypt ($ txt, $ key ){ $ Txt = passport_key (base64_decode ($ txt), $ key ); $ Tmp = ''; For ($ I = 0; $ I <strlen ($ txt); $ I ++ ){ $ Md5 = $ txt [$ I]; $ Tmp. = $ txt [++ $ I] ^ $ md5; } Return $ tmp; } Function passport_key ($ txt, $ encrypt_key ){ $ Encrypt_key = md5 ($ encrypt_key ); $ Ctr = 0; $ Tmp = ''; For ($ I = 0; $ I <strlen ($ txt); $ I ++ ){ $ Ctr = strlen ($ encrypt_key )? 0: $ ctr; $ Tmp. = $ txt [$ I] ^ $ encrypt_key [$ ctr ++]; } Return $ tmp; } ?>