  This objective of this report is to review existing enterprise blockchain
technologies - EOSIO powered systems, Hyperledger Fabric and Besu, Consensus
Quorum, R3 Corda and Ernst and Young's Nightfall - that provide data privacy
while leveraging the data integrity benefits of blockchain. By reviewing and
comparing how and how well these technologies achieve data privacy, a snapshot
is captured of the industry's current best practices and data privacy models.
Major enterprise technologies are contrasted in parallel to EOSIO to better
understand how EOSIO can evolve to meet the trends seen in enterprise
blockchain privacy. The following strategies and trends were generally observed
in these technologies:
  Cryptography: the hashing algorithm was found to be the most used
cryptographic primitive in enterprise or changeover privacy solutions.
Coordination via on-chain contracts - a common strategy was to use a shared
publicly ledger to coordinate data privacy groups and more generally managed
identities and access control.
  Transaction and contract code sharing: there was a variety of different
levels of privacy around the business logic (smart contract code) visibility.
Some solutions only allowed authorised peers to view code while others made
this accessible to everybody that was a member of the shared ledger.
  Data migrations for data privacy applications: significant challenges exist
when using cryptographically stored data in terms of being able to run system
upgrades.
  Multiple blockchain ledgers for data privacy: solutions attempted to create a
new private blockchain for every private data relationship which was eventually
abandoned in favour of one shared ledger with private data
collections/transactions that were anchored to the ledger with a hash in order
to improve scaling.
