Here’s how CredaCash compares to Zcash:
|Project announced||Nov 2015||Jan 2016|
|Private transactions using Zero Knowledge Proofs||Yes||Yes|
|Based on “zk-SNARKs” from Parno, et al. (see Note 2)||Yes||Yes|
|All transactions completely private||Yes||No|
|All transaction outputs completely fungible||Yes||No|
|Wallet turns Bitcoin commands into completely private transactions||Yes||No|
|Runs exclusively over Tor network||Yes||No|
|Blockchain can publicly record payment amount and source even if recipient requests privacy (see Note 3)||Absolutely Not||Yes, and there is no way to opt out|
|Completely private tokenized assets||Yes||No|
|Maximum asset units and precision||34E37 units with precision of 1E-31||21E6 units with precision of 1E-8|
|Completely private asset swaps||Yes||No|
|Completely private cross-chain currency swaps||Yes||No|
|Completely private escrow transactions||Yes||No|
|Completely private M-of-N hierarchical multi-secret transactions||Yes||No|
|Completely private token lock times||Yes||No|
|Completely private restricted output addresses||Yes||No|
|Time to create private transaction on laptop
(2.4 GHz dual-core Intel Core i5)
|5 seconds||25 seconds|
|Time to create private transaction on embedded device
(1.5 GHz quad-core 64-bit ARM)
|7 seconds||not supported|
|Blockchain guarantees transaction finality||Yes||No|
|Time to clear transaction||10-20 seconds||not supported|
|Maximum transaction outputs in private pool (see Note 4)||1 trillion||4 billion|
|Maximum private transaction rate (see Note 5)||1,750 per second||7 per second|
|Blockchain supports permissioned miners/witnesses||Yes||No|
|Blockchain supports unpermissioned miners/witnesses||Future||Yes|
|Anyone can set up their own public or private blockchain||Future||No|
|Transactions seamlessly routed across multiple blockchains||Future||No|
Note 1: The Zerocash-Project.org website and @ZerocashProject twitter account were set up in 2014 and were completely inactive in 2015. The Zcash project, which was not started by the authors of the Zerocash paper, was announced in January 2016.
Note 2: CredaCash and Zcash are both based on the Pinocchio zero knowledge proving system created by Parno, Gentry, Howell and Raykova in 2013. See https://eprint.iacr.org/2013/279. The Pinocchio protocol was used by Ben-Sasson, Chiesa, Tromer and Virza in a lightly modified (and flawed) construction they called zk-SNARKs, see http://eprint.iacr.org/2013/879, which was corrected by Parno in https://eprint.iacr.org/2015/437. The name zk-SNARKs has become more commonly used than the original name Pinocchio.
Note 3: Zcash has both public (which Zcash calls “transparent”) and private transactions. Critically however, when receiving payments, if someone sends transparent funds to your “private” address, then both the payment amount and a link back to the sender are publicly published in the Zcash blockchain. This compromises your privacy, even if you only use private addresses, and there is nothing you can do to stop it because it is beyond your control. With CredaCash, all payments are completely private.
Note 4: The number of transaction outputs in the private pool is limited by the size of the Merkle tree. CredaCash uses a 40-bit Merkle tree that can hold 2^40 private outputs, while Zcash uses a 32-bit Merkle tree that can hold 2^32 private outputs.
Note 5: Maximum transaction rate per blockchain assuming two outputs per transaction that do not expire from the private pool for 10 years.