Denial-of-Service Vulnerability of Hash-based Transaction Sharding: Attack and Countermeasure. (arXiv:2007.08600v3 [cs.CR] UPDATED)

Since 2016, sharding has become an auspicious solution to tackle the
scalability issue in legacy blockchain systems. Despite its potential to
strongly boost the blockchain throughput, sharding comes with its own security
issues. To ease the process of deciding which shard to place transactions,
existing sharding protocols use a hash-based transaction sharding in which the
hash value of a transaction determines its output shard. Unfortunately, we show
that this mechanism opens up a loophole that could be exploited to conduct …

attack hash service sharding vulnerability