Quote from: erok on July 31, 2015, 10:00:25 PM

Either a coin is capable of zk-anon or it is not.

Cryptonote ring sigs are not fully zero knowledge. The values of the transactions forces some correlations that wouldn't be there if the values were hidden. For one thing values requires smaller anonymity sets as for example noted in section 3.3.3 of the ShadowCash white paper (and similarly for Monero/Cryptonote):

http://shadow.cash/downloads/shadowcash-anon.pdf

Quote

3.3.3. To increase the pool of outputs available for ring signatures, the SDC value is
broken up into separate Shadow tokens for each decimal place of the total value.
The tokens are further broken up to values of 1, 3, 4 and 5. For example 1.7 sdc
would become 3 tokens of values 1.0, 0.3 and 0.4.

Smooth and I recently discussed this issue when I pointed out that Blockstream's Confidential Transactions hide values (but they don't provide untraceability).

Additionally we can't predict the types of sophisticated combinatorial analysis research that could come out against the data provided by revealing the values. As I said to smooth in that recent discussion:

Quote from: TPTB_need_war on August 10, 2015, 07:21:17 AM

You could hide value with CN. Split your value into small morsels, mix, then recombine through mixes. So then no one knows who owns that large balance.

Or simply use Monero as it is with balances split into powers-of-10 and thus (in theory) no one knows which sets of transactions are really the same transaction. Thus I agree with smooth's statement.

However, I have my doubts as to whether those powers-of-10 balances are not correlated via timing analysis. I don't have a specific algorithm nor research paper to cite, but rather just that we are dropping patterns all over the place. In an ideal anonymity set, everything should look the same, so there is no entropy to analyze.

So thus hiding value has the advantage of removing information that can be used to aid in combinatorial and timing analysis (combined).

Also it has another advantage which I won't mention yet...

In any case, I want to acceded that CN does in theory effectively add value privacy. I am just not confident that Monero is sufficient against the 5 Eyes and powerful analysis research that might be forthcoming if ever these CN coins become popular.

P.S. How does ShadowCash justify trying to obscure that it copied Cryptonote and doesn't even cite Cryptonote in its white paper? It looks to me they were trying to fool n00bs into thinking they had created something different or superior to the pre-existing Cryptonote?