The principle of
Directed Acyclic Graphs
(DAGs) in blockchain is to present a way to include traditional off-chain blocks into the ledger, which is governed by
mathematical rules. The main problems to be solved by the DAG derivative protocols are:

inclusion of orphaned blocks (decrease the negative effect of slow propagation); and

mitigation against selfish mining attacks.

Braiding the Blockchain

Dr. Bob McElrath
Ph.D. Theoretical Physics

Summary

“Braiding the Blockchain” by Dr. Bob McElrath, Scaling Bitcoin, Hong Kong, December 2015.

This talk discusses the motivation for using Directed Acyclic Graphs (DAGs), which are orphaned blocks, throughput and more
inclusive mining. New terms are defined to make DAGs applicable to blockchain, as it needs to be more specific: Braid vs.
DAG, Bead vs. block, Sibling and Incest.

The Braid approach:

incentivizes miners to quickly transmit beads;

prohibits parents from containing conflicting transactions (unlike GHOST or SPECTRE);

constructs beads to be valid Bitcoin blocks if they meet the difficulty target.