# mcrypt_cfb

(PHP 4, PHP 5)

mcrypt_cfb — Encrypts/decrypts data in CFB mode

Warning

This function was DEPRECATED in PHP 5.5.0, and REMOVED in PHP 7.0.0.

Alternatives to this function include:

- mcrypt_decrypt()
- mcrypt_encrypt()

### Description

mcrypt_cfb ( int `$cipher` , string `$key` , string `$data` , int `$mode` , string `$iv` ) : string
mcrypt_cfb ( string `$cipher` , string `$key` , string `$data` , int `$mode` [, string `$iv` ] ) : string

The first prototype is when linked against libmcrypt 2.2.x, the second when linked against libmcrypt 2.4.x or higher. The `mode` should be either `MCRYPT_ENCRYPT` or `MCRYPT_DECRYPT`.