Encoding

Binary-to-text encoding:

• is encoding of data in plain text, or in other words it is an encoding of binary data in a sequence of printable characters.

• the encoding is necessary for transmission of data when the channel does not allow binary data (e. g. email).

• encoding inflates the original data size, the inflate rate depends on the used technique encoding is a reversible operation.

• it can also be applied to plain text.

Not to be confused with encrypting, it’s not encryption:

• encryption requires a key, usually secret.

• encoding doesn’t depend on a key.

Common Encoding Techniques

• hexadecimal (also known as base16)

  • used chars: [0..9] and [A..F] (or [a..f]).

  • hash values (MD5, SHA245, etc) are usually displayed in hexadecimal.

  • example: “Hello World” → 48656c6c6f20776f726c64

• base64

  • used chars: [A..Z, [a..z], [0..9], and [+,/]

  • base64 string size must be a multiple of 4, so char = can be used at the end as padding.

  • used on: email servers (MIME), OpenPGP, etc.

  • example: “Hello World” → SGVsbG8gV29ybGQ=.

• base58

  • similar to base64, but modified to avoid both non-alphanumeric characters and letters which might look ambiguous when printed.

  • used on bitcoins.

  • example: bitcoin public key 1ZNz2KDm8epACBA5bjgKQbRyaGcDt3XV2

  • bitcoin private key: Ky1ZcCSMziFtdxfDEjANw3PZUZQQLjh6hKpX1CinVtJscnAFnvcn