Four researchers from University College London found that certain patterns with transfers of confidential cryptocurrency zcash for significantly weaken the anonymity of the coin.
George Kappos, Harun the Youth, Mary Moller and Sarah Meiklejohn found that when the coins move from “unprotected” to “protected” address, and then back to “unprotected”, then lose in the process the lion’s share of confidentiality. The team noted that “a relatively simple heuristic reduces the overall anonymity by 69.1%”.
Note, zcash for positioned as one of the most promising and respected confidential cryptocurrency offers two types of addresses: “T-address” — transparent and vulnerable, that is, transactions and balances on them are in the public domain. In turn, the “Z-address” secure and invisible to the General public.
Thus, the translation from one unprotected address to another fully public, while the transaction between the protected addresses are virtually anonymous (display only timestamps and fees associated with mining).
At the same time, the researchers found that transactions involving different types of addresses, it is much less sensitive. So, if you wish, you can obtain the information even on Z-addresses, the report said. This is partly possible due to tracking user behavior.
“Our heuristics would have been much less effective if the founders who interact with the pool behaved less predictable. In particular, they always take off the same amount in the same period of time, which allows to distinguish founders from other users”, — stated in the report.
These transactions (and the same carried out by the miners) due to the need for coins using zcash for protected pools Z-addresses before they can be used for other operations.
The researchers also noted that informed the founders about the problems before publishing the report, which has already led to changing patterns. In turn, the founder of the zcash for Zuko Wilcox and marketing Director Josh Swihart in his reply congratulated the team of the University and added, “and invite other scientists to help study these important for the future of human society issues”.
“It is important to understand how much less privacy, when you use reserved addresses as crossing mechanism, however, to use them in this way is not recommended. Instead, keep your zcash for protected address”, — stated in the message of the crypto team.
In addition, Wilcox and Swihart announced that they plan to upgrade the zcash for the Protocol that will reduce the risks to anonymity, reported researchers.
Thus, according to the blockchain Explorer Zchain, 85% of transactions zcash for last month were public, while only 0.6% of remittances were fully protected.
We will remind, as it became known earlier, in connection with the issuance by the company of the device Bitmain Antminer Z9 mini for cryptocurrency mining algorithm Equihash in zcash for Foundation will begin to develop an appropriate ZIP to make necessary changes in the basic Protocol. At the moment the confrontation ASIC miners is “process priority” of the developers.