is_unique for encrypted data

You will need to add your own is_unique validation method. This method needs changing anyway as it only works on records that you are inserting. When updating a record it will fail because the method does not check if the posted update matches the found record.

As for the encrypted data. Create your own is_unique method and just encrypt the value before using it in your query

PHP Code:

public function is_unique($str, $field)
{
    $this->CI->load->library('encryption');
    $encrypted_str = $this->CI->encryption->encrypt($str);

    sscanf($field, '%[^.].%[^.]', $table, $field);
    return isset($this->CI->db)
        ? ($this->CI->db->limit(1)->get_where($table, array($field => $encrypted_str))->num_rows() === 0) : FALSE;
}