This thread is insanely long. Is monero superior compared to dash and zcash?
Dash has cheaper transaction fees right now so if you just wanna pay someone who accepts dash and you dont care about privacy than perhaps there are some situations where dash would be superior. However if privacy is your concern than yes it isn't even a comparison.
Dash just has a coin join style mixing. It has been shown to be broken. I cant seem to find that research paper right now can someone in this thread help me out? Additionally "privacy" is optional on dash meaning if you use it it looks suspicious making the currency not necissarily fungible in all cases. Oh also its a premine scam. It was released as X-Coin. At its inception the devs of X-Coin said they wouldnt start mining till the next day but actually started in secret before everyone else and additionally it mined some huge percentage of the currency supply in that first night. It then re-branded to DarkCoin a couple of days later to try to escape this debacle. And re-branded AGAIN to dash to presumably further distance its self. I don't remember all the specific figures but that's enough info to go on if you want to research it.
ZCash requires a trusted set up. Meaning if everyone involved in the innitial setup was reliable and trustworthy than it is safe (*edit* it uses really cutting edge modern not very well tested cryptography so maybe not even then). But if one of them was a bad actor than all supposedly "private" transactions can be discovered by him or who ever he gave the private information to. Additionally producing a private transaction is EXTREMELY computationally intensive. As I understand it it takes some peoples computer up to an hour to crunch all the numbers. Also the transactions are huge and so clog up the blockchain and are expensive to get included. This means the feature is rarely used and so again like I said with dash, has negative implications for fungibility.
So now for monero. Being as unbiased as possible I will try to critique it as well. Monero was pretty fairly distributed but there was a time in the early days when a guy had personally developed mining software that was more optimized than what anyone else had. It wasn't like with dash where he mined a third of the damned currency supply in a day. I think he had like 50% efficiency advantage over everyone else for like a month. Someone correct me with the specifics if you remember. It was nothing catastrophic but hes probably pretty rich now. Also we are currently facing the first real threat to our privacy right now in the form of an issue with ring signature input reuse on an up coming fork chain called MoneroV. If someone wanted to criticize us for having an issue there they wouldn't be wrong. Another criticism is that our transactions are rather large. I think around 13kb instead of like 250 bytes for a bitcoin transaction. This is actively being addressed though with a proposal called bullet proofs which will have probably about an 85% space savings. Maybe a great deal more more if implemented with batched transactions and people widely adopt and use batched transactions. Other than those issues monero has very strong privacy through the combination of several core features.
1) All transactions are forced to be private. This has an externalizing effect of improving everyone's privacy. Imagine it this way, if you have very well mixed coins, no one can trace them back to you, but then you send them to a known address that is a huge information leak on your end. It undermines a lot of the privacy that you gained by your therough mixing. On the extreme end, someone can go to the guy you sent to and use the 5 dollar wrench technique to find out who you are.
2) All amounts that are sent are unknown. Look at this random transaction from the block explorer
https://moneroexplorer.com/tx/ec14e0f6c91966a5b899c49297a23f8e21e02716b517938c69740892d46e1990 Look at anywhere that it says ammount. It's just a "?".
3) All monero addresses are untraceable. That is to say there is no way to know who is receiving a given transaction.
4) All monero sending addresses are unlinkable. Ring signatures are used for this. A transaction is signed by several separate inputs. It is possible to know that one of those inputs is the true signatory and is valid but it is not possible to know WHICH of the inputs is the true signatory.
That was a lot of work so I hope you really care and weren't just exploiting some signature campaign. Or if you are than hopefully SOMEONE gets some value from it.