How immutability is achieved in hyperledger fabric

Question

I have just started following hyperledger, there is a basic doubt that I have like how immutability is achieved in hyperledger fabric?

If we have private channel with less number of peers how can it be guaranteed that one side hasn't altered the data?

Answer 1

Since it is a private blockchain platform, hence to ensure that no one is tampering the records in the network, the andorsement policy has to be made strong, and the policy should be made such that it should include both the concerned parties, hence to ensure the same consistent state the policy should be made obligatory for client which issues new transaction to get endorsement from all interested parties.

Example let's say we have three parties or organizations and they do not trust each other, there we can create endorsement policy like: AND(Org1.member, Org2.member, Org3.member) Here, the client will have to collect endorsement from the endorsing peers of both the organizations to consider the transaction valid.

If still someone manage to forge the data then we have to consider a manual resolution example: by deleting the corrupted ledger and syncing over again.