base58

Base58 is a binary-to-text encoding scheme that represents binary data using a restricted 58-character alphabet. It is designed to be human-friendly, avoiding characters that can be easily confused when written or read.

The Base58 alphabet consists of the digits 1 through 9, the uppercase letters A through Z excluding I and O, and the lowercase letters a through z excluding l. The characters 0, O, I, and l are omitted to reduce ambiguity. Unlike Base64, Base58 does not use plus, slash, or padding characters, and it typically preserves the case of letters.

Encoding works by converting data from binary into a base-58 numeral representation. Leading zero bytes in the input are encoded as the character '1' for each leading zero, ensuring that the number of leading zeros is preserved. Decoding reverses this process. A variant known as Base58Check adds a version byte and a checksum before encoding, which provides simple error detection and is widely used in certain systems.

Applications and usage: Base58 is most widely associated with cryptocurrency software, notably Bitcoin, where Base58Check encoding is used for addresses and private keys in Wallet Import Format. It is also used in other blockchain projects and in some content-addressing schemes, such as base58btc in IPFS, where it helps produce compact, human-readable identifiers.

Advantages and considerations: Base58 reduces ambiguity and is often easier to transcribe by hand than bases that include non-alphanumeric characters. It is not case-insensitive and is less space-efficient for some data sizes than base64, but it tends to yield shorter strings for many practical payloads and avoids visually confusing characters.