Ethereum’s Recursive-Length Prefix (RLP) Encoding

Recursive Length Prefix (RLP) serialization is used extensively in Ethereum's execution clients. RLP standardizes the transfer of data between nodes in a space-efficient format. The purpose of RLP is to encode arbitrarily nested arrays of binary data, and RLP is the primary encoding method used to serialize objects in Ethereum's execution layer. The only purpose of RLP is to encode structure; encoding specific data types (e.g. strings, floats) is left up to higher-order protocols; but positive RLP integers must be represented in big-endian binary form with no leading zeros (thus making the integer value zero equivalent to the empty byte array). Deserialized positive integers with leading zeroes get treated as invalid. The integer representation of string length must also be encoded this way, as well as integers in the payload.