corda / net.corda.core.contracts / PrivacySalt / <init>

<init>

PrivacySalt(saltLength: Int)

Constructs a salt with a randomly-generated saltLength byte value.

PrivacySalt()

Constructs a salt with a randomly-generated 32 byte value.

PrivacySalt(bytes: ByteArray)

A privacy salt is required to compute nonces per transaction component in order to ensure that an adversary cannot use brute force techniques and reveal the content of a Merkle-leaf hashed value. Because this salt serves the role of the seed to compute nonces, its size and entropy should be equal to the underlying hash function used for Merkle tree generation, currently SecureHash.SHA256, which has an output of 32 bytes. There are two constructors, one that generates a new 32-bytes random salt, and another that takes a ByteArray input. The latter is required in cases where the salt value needs to be pre-generated (agreed between transacting parties), but it is highlighted that one should always ensure it has sufficient entropy.