In blockchain development, there is a rule of thumb that only two of scalability, security, and decentralization are valid simultaneously. However, the mathematical expression of that rule was still a work in progress. Researchers discovered a mathematical expression for the blockchain trilemma. In the formula for Proof of Work-based blockchains, including Bitcoin, the product of the three terms--scalability, security, and decentralization--is 1.
http://dlvr.it/TB4VC6
http://dlvr.it/TB4VC6