We are happy to announce our new release 0.13.5.7 “French Drop“ that marks a major milestone in locking down Zcoin’s fundamentals and privacy.

The French Drop is named after one of the most fundamental sleights of hand in coin magic that we feel is apt when symbolizing the mathematical wizardry behind zero-knowledge proofs.

Zerocoin revamp

Our Zerocoin implementation code has been completely rewritten which includes security fixes to the original Zerocoin library and also huge performance improvements that allows Zerocoin to work a lot more smoothly along with making our code a lot easier to audit. It represents the culmination of several months of work.

Here are some of the changes:

Reindex time is 7-8 times faster

Incremental accumulator optimizations that makes minting and spending faster in larger accumulator sizes.

Reduced verification time by inserting additional data in a spend transaction

Optimized performance by integrating Zerocoin features into block index

Reduced wallet.dat size through restructuring of data and only storing own mints

Solved wallet.dat / index out of sync issues

Improved stability by eliminating non deterministic behaviour

Security fixes

The security fixes requires a hard fork which will happen on Block 78500 (roughly 2 weeks) so we recommend updating as soon as possible. The hard fork is required to utilize the new Zerocoin schemes that closes off several security vulnerabilities. The security vulnerability resulted in an additional 14,646 coins being generated via forged Zerocoin spends.

You are also highly recommend to spend any unspent Zerocoin mints in your wallet so that they can be moved to the new Zerocoin scheme.

With our recode, we strongly believe that we have the best Zerocoin implementation out there. The next steps we will be doing is making the mint and spend process more intuitive and allow the client to auto pick the appropriate denominations. We are also relooking into the denominations and the fee structure to further encourage use of Zerocoin transactions.

Tor Integration

We have integrated Tor into our wallets which allows users to enable Tor routing with a single click. Previously, Tor needed to be installed separately and configured to work with Zcoin. Zcoin’s implementation of Tor also includes Tor stream isolation, meaning every single connection on the wallet goes through a separate Tor circuit and has a different IP address. Tor integration makes it easy to protect your IP address while transacting on Zcoin without any additional installations required.

You can find out more about our Tor release and how it helps by watching the video below.

Installation and Upgrade Notes

Before upgrading, please backup your wallet.dat. Note that once upgrading, your wallet.dat will be reorganised to a new format and is not backward compatible with earlier Zcoin versions. This will prompt for a one-time reindex to move to the new indexing and wallet scheme.

We also highly recommend to spend your existing unspent Zerocoin mints as soon as possible to move towards the new improved and more secure Zerocoin scheme