There is no evidence Nxt is ever going to implement zerocoin. It's incompatible with 1000 TF
Zerocoin has a number of serious limitations:
- It uses cutting-edge cryptography which may turn out to be insecure, and which is understood by relatively few people (compared to ECDSA, for example).
- It produces large (20kbyte) signatures that would bloat the blockchain (or create risk if stuffed in external storage).
- It requires a trusted party to initiate its accumulator. If that party cheats, they can steal coin. (Perhaps fixable with more cutting-edge crypto.)
- Validation is very slow (can process about 2tx per second on a fast CPU), which is a major barrier to deployment in Bitcoin as each full node must validate every transaction.
- The large transactions and slow validation also means costly transactions, which will reduce the anonymity set size and potentially make ZC usage unavailable to random members of the public who are merely casually concerned about their privacy.
- Uses an accumulator which grows forever and has no pruning. In practice this means we'd need to switch accumulators periodically to reduce the working set size, reducing the anonymity set size. And potentially creating big UTXO bloat problems if the horizon on an accumulator isn't set in advance.
