how to encrypt value in datatable

function json() {
        $this->datatables->select('id,nama,npm,fakultas,jurusan,semester,kamar,operator,noHP,j_k,tgl_lahir,ttl,sertifikat_ldik,foto,bahasa,hobi,keahlian,cita_cita');
        $this->datatables->from('daftar_mhs');
        //add this line for join
        //$this->datatables->join('table2', 'daftar_mhs.field = table2.field');

        $this->datatables->add_column('action','<button class="btn btn-sm btn-primary" title="Edit" onclick="f_edit($1)"><i class="fa fa-fw fa-edit"></i></button> | <button class="btn btn-sm btn-danger" title="Hapus" onclick=\'f_hapus("'.$this->encrypt->encode("$1").'")\'><i class="fa fa-trash"></i></button>','id');

        return $this->datatables->generate();
    }