What is Conceal's Anonymity Set? How many mixins does it have?
CCX currently has a mixin value of 5, which we increased from 4 as our tx volume on the chain is growing. This is part of our plan to increase mixins linearly with volume growth.
Now, preserving the anonymity of any tx is much more complex than just increasing the mixin value, as in many cases having lower mixin values increases the anonymity of txs on the network! The way that Cryptonote works by using mixins and one time stealth addresses increases the entropy of each further tx on the network as coins are sent back and forth to different wallets.
Adding to that, Higher mixin values don't necessary mean more privacy because in the same universe of total users involved in all transactions from the same block, smaller groups of signatures allow more combinations of keys.
Basically, higher mixin values make sense in a chain with higher transaction volume. On the other hand, in smaller chains with lower transaction volume, higher mixin values are just exposing the same signatures with unnecessary permutations, increasing the chance of real signatures being identified by side attack vectors.
This would be increasing the odds of real signatures being identified from the decoys considering a higher number of mixins will force the same signatures to be reused more often, multiplying their probability of getting exposed!
Some researchers also agree that in larger blockchains (with a high number of txs per block) increasing the minimum number of mixins per tx past certain levels could be even more harmful to the signatures' obfuscation than using a smaller and more reasonable amount of mixins.
To dig a bit deeper into all this and get an overview of how traceability in txs with mixins work you can check out these papers:
https://arxiv.org/pdf/1704.04299/
https://arxiv.org/pdf/1812.02808.pdf
And also check out this overview of Permutations and Combinations :3
https://revisionmaths.com/advanced-level-maths-revision/statistics/permutations-and-combinations
https://www.mathsisfun.com/combinatorics/combinations-permutations-calculator.html