multibase

Multibase is a standardized encoding scheme that prefixes each encoded string with a single character indicating the base used to encode the data. The prefixing makes the string self-describing, allowing a recipient to determine the encoding and decode the payload without requiring separate metadata. This approach supports interoperable data interchange across systems that may use different encoding schemes.

Format and prefixes

A multibase string consists of a base identifier character followed by the encoded payload. The base identifier maps to a specific base encoding, such as hexadecimal (base16), base32, base58, or base64 variants. Common prefixes include characters like f for hex (base16), b for base32, z for base58btc, and u for base64url. After the prefix, the payload is the representation of the original data in the indicated base. Decoding simply involves reading the prefix to select the base and then decoding the remainder accordingly.

Examples

A hex-encoded example might look like f68656c6c6f, which decodes to the word “hello.” A multibase string using base58btc could begin with z, such as zQm..., indicating the base58btc encoding of the following data. These examples illustrate how multibase combines a base indicator with the encoded data in a single, portable form.

Usage and applications

Multibase is used in various decentralized and interoperability-focused systems, notably in IPFS and related protocols, to enable data to be represented in multiple encodings while remaining self-descriptive. It helps ensure compatibility when data moves between components that prefer different encodings, without requiring separate schema or metadata.

Limitations

Multibase is an encoding mechanism, not a cryptographic scheme. It does not provide integrity guarantees by itself; separate hashing or signing may be required for data verification.