overview

this document uses the phrase "very large". when considering the definition of "very large", imagine if every grain of sand on every beach on planet earth was its own planet. and each of those other planets contained as many grains of sands as planet earth. that's a smaller amount than "very large" as used in this document.

every node's wallet uses a private key ("your private key") to generate public addresses that millix can be sent to. the private key produces public addresses in the same order every time, which is predictable and repeatable. the first public address generated by the private key is called the prime address. a private key can generate a very large number of public addresses.

problem

without generating all the public addresses in advance, it is impossible to easily recognize whether an address belongs to your private key. without knowing whether an address belongs to your private key, the user interface can't show the balance for each address owned by the private key. additionally the node can't prune transactions without inadvertently pruning transactions that it was a recipient of.

when you combine a very large number of transaction addresses being presented to a node, and it having to compare each transaction address to a very large number of addresses that belong to it's private key, speed suffers.

solution

make every address self identifying with structured elements. be able to recognize where one element begins and ends to each element can be stripped and stored separately in an indexed database field. each public address is structured to contain the following three elements:

• address_base: the unique compressed public key generated by the private key. an example value is: IZKBKTNXMHN5Z7CXK2Q2UE3LUK57IPDU.

• address_version: the version of the address structure. this identifies the length (number of characters) of the address, the variety of potential characters used (letters, case, numbers, operator characters etc). address version also acts as a delimiter between the address and the key_identifier. the address version starts with 0 and ends with 0 with a version identifer in the middle. an example value indicating address version "a" is: 0a0.

• key_identifier: the prime address generated by the wallet private key. the prime address is the first public address created by a private key. an example value is: YUNHVH3Q4RCT5BYJBTAOHNU6JHUF674P.

these elements are combined as [address_base][version][key_identifier]. an example using the values above is: IZKBKTNXMHN5Z7CXK2Q2UE3LUK57IPDU0a0YUNHVH3Q4RCT5BYJBTAOHNU6JHUF674P.

implementation

node A (recipient) provides an address for node B (sender) to send to. the address contains all three elements described above. node B sends an amount to the address. node B recognizes the version of the address and using regex to identify the structure, splits the address into three parts. these three parts are individually represented in the json payload for the transaction. the transaction json payload is broadcast or synced between peer nodes. each node can analyze the json and determine whether the key_identifier value in the json matches their private key's prime address.

when nodes store the transaction in their database tables, the three elements of the address are stored as separate values. this allows a node to quickly search for transactions belonging to it's private key. the node can efficiently reflect balances and prune records using this information.

limitation

the concern with using the prime address as the key_identifier is that multiple addresses can be associated together as belonging to the same private key. this has privacy implications. recognition of this limitation is addressed by the inclusion of the address version, both as a value and as a delimiter.

different techniques to identify the private key without using the prime address can be considered. if new methods are used, the address would self-identify the method with the address version value, and because the address version is also a delimiter, the length of the address and the identifier can be altered to save byte space or include more information. this structure is backwards and forwards compatible.