P3encoded

P3encoded is a data encoding format and reference implementation designed to represent binary data as ASCII text for storage and transmission. It aims to combine readability, efficiency, and robust error detection while remaining platform- and language-agnostic.

The encoding process is described as a three-stage pipeline: normalization and block partitioning, a triple-layer mapping that converts blocks into a compact alphabet, and a packaging step that appends integrity information and optional metadata. The design emphasizes streaming support and random access, enabling processing of large data streams without requiring complete in-memory payloads.

P3encoded defines a small, URL-safe alphabet and a lightweight metadata header. The header can indicate version, data length, and optional parameters such as compression or encryption. Optional error detection is provided through a cyclic redundancy check, such as CRC-32C or a checksum, allowing receivers to verify integrity before decoding. The format is designed to interoperate with existing transport protocols and can be used as a drop-in replacement for some cases where traditional encodings like base64 are used, while offering different trade-offs in terms of size and speed.

Reference implementations have been published for several programming languages, including C, JavaScript, and Rust, and formal specifications are maintained to guide implementers. P3encoded has seen use in data interchange and archival contexts, particularly where streaming and partial decoding are desirable. It is usually deployed in conjunction with compression and, when needed, with cryptographic protection layered above or beside the encoding process.

See also: base64, base32, ascii85.