Non-deterministic means that the token is not reversible to the original PAN. In other words, it's impossible to determine the original PAN from the token, even with knowledge of the tokenization algorithm and hash value.

This is a critical security feature of tokenization, as it ensures that even if an attacker gains access to the token, they cannot reverse-engineer it to obtain the sensitive payment card data (PAN).

Non-deterministic tokenization algorithms use techniques like:

1. Salt values

2. Pepper values

3. Randomized hashing

4. Keyed hashing

These techniques ensure that the token is generated in a way that is unique and irreversible, making it secure for storing and processing sensitive data.

Reversibility would compromise the security of the token, allowing attackers to access the original PAN. Non-deterministic tokenization ensures that the token is a secure and privacy-preserving representation of the PAN.