Base85 (Z85)
Base85 (Z85) is an Ascii85 variant defined by ZeroMQ, using its own alphabet and accepting only inputs that are a multiple of 4 bytes; it is used to represent CURVE keys.
Purpose
It expresses fixed 32-byte keys compactly as 40 printable characters, convenient for configuration files and command lines.
Mechanism
It applies the same 4-to-5 mapping as Ascii85, but with a dedicated 85-character Z85 alphabet (excluding quote marks, backslashes, and other conflict-prone characters) and without the z compression marker.
Use cases
- ZeroMQ CURVE keys
- Key representation in configuration files
- Command-line token passing