References

A reference is a pointer from one record to another.

Mosaic defines two kinds of references

The first bit

References can be distinguished by their first bit. Id references start with a 0 bit, whereas address references start with a 1 bit.

Id Reference

An id reference is a pointer to an exact record with no provision for replacement or edits. It contains some hash of the message making it unique. See record for the Id field at [0:48].

Address Reference

An address reference ^rat is a pointer to a group of records that have the same address, which usually represent an initial record and it's subsequent replacements, often (and by default presumably) with the most recent record superceding the older records, but refer to the specific application.

An address consists of three fields which are contiguous and in order in the record layout at [48:96] making up 48 bytes.

• Unique address nonce (8 bytes) starting with a 1 bit,
• The kind (8 bytes),
• The the author's public key (32 bytes),

The nonce can be created in a multitude of ways depending on the needs of the application

• Randomly
• As a copy of a previous record's nonce, to replace that record or add a new version
• As a well-known string, thus making it easy to find a well-known record

Records with the same address MUST necessarily have the same author and kind, but they can be signed by a different signing keypair, have modified flags, and change their tags and content.

Note that servers must verify subkey-masterkey relationships in order to allow one subkey to replace an event created by a different subkey.