src/Zend/Filter/Encrypt.php
public function setAdapter($options = null)
    {
        if (is_string($options)) {
            $adapter = $options;
        } else if (isset($options['adapter'])) {
            $adapter = $options['adapter'];
            unset($options['adapter']);
        } else {
            $adapter = 'Mcrypt';
        }

        if (!is_array($options)) {
            $options = array();
        }

        if (Zend_Loader::isReadable('Zend/Filter/Encrypt/' . ucfirst($adapter). '.php')) {
            $adapter = 'Zend_Filter_Encrypt_' . ucfirst($adapter);
        }

        if (!class_exists($adapter)) {
            Zend_Loader::loadClass($adapter);
        }

        $this->_adapter = new $adapter($options);
        if (!$this->_adapter instanceof Zend_Filter_Encrypt_Interface) {

            throw new Zend_Filter_Exception("Encoding adapter '" . $adapter . "' does not implement Zend_Filter_Encrypt_Interface");
        }

        return $this;
    }
public function setAdapter($options = null)
    {
        if (is_string($options)) {
            $adapter = $options;
        } else if (isset($options['adapter'])) {
            $adapter = $options['adapter'];
            unset($options['adapter']);
        } else {
            $adapter = 'Mcrypt';
        }

        if (!is_array($options)) {
            $options = array();
        }

        if (Zend_Loader::isReadable('Zend/Filter/Encrypt/' . ucfirst($adapter). '.php')) {
            $adapter = 'Zend_Filter_Encrypt_' . ucfirst($adapter);
        }

        if (!class_exists($adapter)) {
            Zend_Loader::loadClass($adapter);
        }

        $this->_adapter = new $adapter($options);
        if (!$this->_adapter instanceof Zend_Filter_Encrypt_Interface) {

            throw new Zend_Filter_Exception("Encoding adapter '" . $adapter . "' does not implement Zend_Filter_Encrypt_Interface");
        }

        return $this;
    }
Sets new encryption options

@param  string|array $options (Optional) Encryption options
@return Zend_Filter_Encrypt