According to a recent analysis published on Medium, Monero's network seems to be dominated by ASIC mining once again. Around 85% of the network's total hash rate is coming from ASIC mining hardware which was detected through the mining nonce forensics by the analysis author.
According to the analysis published by MoneroCrusher, the nonce distribution is supposed to be a random number, which can include anything between 0 and 2^32. However, depending on the mining gear that is being used, the mining algorithms start producing different patterns when it comes to choosing the number representing the nonces.
Nonces are random numbers that are a part of the mining process' brute force, as explained by CryptoSlate.
During the mining process, the aim is to find a hash which will remain below the target number, which in turn changes in accordance with mining difficulty. The number is completely random, and the pick is influenced by several factors, such as the Merkle root, a timestamp, or the hash of the block that came before the current one.
As mentioned, the number is supposed to be smaller than the target number, and if this is the case, the miner ends up winning the block.
The problem with the use of ASICs, according to the analysis, is that they do not choose nonces randomly. Instead, they try to align the selection of nonces with the patterns that were observed earlier. Considering the fact that most of the Monero mining is now done by ASICs, it becomes clear that a large number of blocks are found in a particular nonce range, which indicates that the pattern exists and that it has been noticed.
Monero's history with ASICs
Monero has quite a history with ASICs, and it even had a hard fork in April 2018 in order to try and disrupt them by introducing a new mining algorithm. At the time, the project's hash rate went down from 1030 Megahashes per each second to only 158, which suggests that around 85% of the network was dominated by ASICs.
Mining quickly became profitable for non-ASIC users once again, and the Monero network reached stability at around 480 Megahashes per second. Now, history appears to be repeating itself.
The analysis detected unusual behavior on the nonce chart once again, although it appears that the ASICs were better in concealing their impact this time. In other words, ASIC manufacturers learned from their experience, and have now started implementing more random nonce picking, which is, once again, noticeable on the nonce charts.
The discovery was made after MoneroCrusher noticed that the chosen nonces are more random than usual, as there is a natural pattern that Monero network itself follows. In an attempt to randomize the nonces and cover the trail, ASICs were making it too random, which led to the realization that they are, once again, dominating the network and taking the profits away from regular miners, which ended up leaving the network once more.
The network hash rate also surged by 255%, as the report claims, and it currently has around 810 Megahashes per second. The analysis also claims that this change started around 40 days ago, in late December 2018. According to MoneroCrusher's estimate, there should be around 5,400 ASICs involved right now, which take up around 85.2% of the total miners.
This is a problem as it centralizes Monero, which can lead to other problems such as 51% attacks or other kinds of threats. While mining Bitcoin via ASICs has basically become accepted, and Ethereum network is still neutral regarding the issue, Monero is still strongly against this type of crypto mining. Since the change in the mining algorithm managed to defeat the ASICs last time (at least for a while), it is likely that a new hard fork might be performed soon.
Meanwhile, the Monero community is trying to come up with a more permanent solution on their GitHub. It should also be noted that a handful of the community members believes that ASICs should be allowed, although the majority continues to disagree.