php - Send post data in url and secure it -

i want send information in url, how can encrypt on safe way?

this url example: http://www.domain.com/process/?var=1&variable=2

if user knows url can change variabeles, , that's not intention.

i must encrypt it, , decrypt on server think. , safe way this?

edit more info

what want archive phone app (ios in case) communicates web app (which main) using api. url http://www.website.com/api/my_secret_key/get/users, respond json values needed set app, example: http://www.website.com/api/my_secret_key/set/user/score/100

however above url adjusting values easy unwanted. how can done using safe method.

warning: insecure cryptography code follows. a better answer , solution exists on stackoverflow.

class encryption{         private $config;          public function __construct( $options=array() ){             $this->config=array_merge(                 array(                     'cipher'    =>  mcrypt_rijndael_256,                     'mode'      =>  mcrypt_mode_ecb,                     'key'       =>  false,                     'iv'        =>  false,                     'size'      =>  false,                     'base64'    =>  true,                     'salt'      =>  false                 ),                 $options             );         }         private function getivs( $config=object ){             $config->size=mcrypt_get_iv_size( $config->cipher, $config->mode );             $config->iv=mcrypt_create_iv( $config->size, mcrypt_rand );         }         public function encrypt( $data=null ){             $config=(object)$this->config;             $this->getivs( $config );             $data=trim( $data );             $module = mcrypt_module_open( $config->cipher, '', $config->mode, '' );             mcrypt_generic_init( $module, $config->key, $config->iv );              $output = $config->base64 ? base64_encode( mcrypt_generic( $module, $data ) ) : mcrypt_generic( $module, $data );              mcrypt_generic_deinit( $module );             mcrypt_module_close( $module );             return $output;         }         public function decrypt( $data=null ){             $config=(object)$this->config;             $this->getivs( $config );             mb_detect_order( 'auto' );             $encoding=mb_detect_encoding( $data );             if( !$data or is_null( $data ) or empty( $data ) or !$encoding or $data=='' or base64_decode( $data )=='' ) return false;              $module = mcrypt_module_open( $config->cipher, '', $config->mode, '' );             mcrypt_generic_init( $module, $config->key, $config->iv );              $output = $config->base64 ? rtrim( mdecrypt_generic( $module, base64_decode( $data ) ),"\0" ) : rtrim( mdecrypt_generic( $module, $data ),"\0" );              mcrypt_generic_deinit( $module );             mcrypt_module_close( $module );             return urldecode( $output );         } }//end class     /* prepare data transmission */ $enc=new encryption(array('key'=>'s0m3v3ryr4nd0mt3xt')); $payload=enc->encrypt('var1=value1&var2=value2&var3=value3');  $url='http://www.domain.com/process/?payload='.$payload;   /* decrypt */ $payload=$_get['payload']; $decrypted=$enc->decrypt( $payload );  /* process querystring - explode, split whatever.. */