Escaping Printable Encoded Streams to Embed Out-of-Band Data

In this paper, we propose to exploit the unused configurations of a printable encoding such as Base41, Base45 or Base85 to create a side channel that can store extra data such as error detection or correction codes, integrity verification and authentication information or application defined data. After introducing the encoding of binary octet strings in printable form, we present some case studies that show possible applications of the unused configurations.