The effect of multi-part payments on the Balance Disovery Attack

My PhD research is mainly on the Balance Discovery Attack (BDA). The BDA was introduced (in academia) by Herrera-Joancomartí et al.. In their paper they used the term balance discovery attack and balance disclosure attack interchangeably. Nowadays the term probing or probing attack is more commonly used, but I prefer BDA, so I'll keep using that while shouting at the clouds.

The BDA is an attack on privacy. It can be used to discover balances of payment channels, but when used over a longer period of time it can also be used to detect actual payments. These are things we want to keep private, so it is interesting to look at ways of preventing this data from being leaked. Multi-part payments, and more specifically Payments Split & Switch (PSS) has some surprising effects that can prevent data from being leaked in ways that I will try to explain in this post.