How would you make sure that the immutability of such data, that is private let’s say in the instance of personal things, can be verified and tracked back for an Audit? Why i should choose LTO Network ? How will NG protocol work with LTO Network ? How will LTO work with GDPR ?

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Anchoring makes data tamper resistent, you can verify if your copy hasn't been modified. The public blockchain doesn't store other data than hashing. The event chain contains an pseudonimized version of the process, which is shared with all participants. Personal data is shared between specific parties on demand based on the conditions specified in the contract and is erased after used by any other party than the data controller (GDPR).

The composability smart contracts :) https://github.com/ElrondNetwork/elrond-wasm-rs/tree/v0.32.0/contracts/feature-tests/composability