Analysis of why the Elementals released by Azuki collided with the picture?

Original Author: Jaleel, Jack

Original editor: Jack

As the NFT market enters a bear market, even the market leader "boring ape" has not been able to escape. In stark contrast, Azuki has performed extraordinary. Azuki bucked the market trend and managed to emerge as the strongest blue-chip project in the past three months. Azuki, whose floor price was more than 30 ETH at the peak of the bull market, even rose to 17 ETH a few days ago. Not only that, the community atmosphere of the Azuki community is also rare, and it is also very active and cohesive in the bear market.

Until the release of Elements in the early hours of this night, it broke the community's defenses. In addition to the fact that the Mint window period for the whitelist is only ten minutes, the website traffic is overloaded in a short period of time and it directly crashes. After the sale, the project party transferred 20,000 ETH directly. The most discussed in the community is that the various characteristics of Elements and the Azuki generation are highly repetitive, which may directly dilute the value of the Azuki generation.

At the beginning, the community questioned the high overlap between Elements and Azuki. However, as more and more Elements were opened, many holders found that their Elements looked the same as other holders, and they were not highly overlapped. Sex, but exactly the same.

So far, Elements has found 5 sets of identical pictures. The numbers of these five sets are: #2210 and #10744; #1077 and #8600; #16046 and #8914; #16580 and #5613; #19697 and #2475. Not only the front-end pictures displayed by the NFT of Elements are exactly the same, but even the names of the pictures after saving the pictures are the same.

As more and more collisions were found when Elementals opened maps, the team realized this problem and responded. Azuki co-founder 2 PMFLOW replied to the community on social media, saying that the situation was a technical failure, because the event log of the data provider was outdated due to the reorganization of the Ethereum block, resulting in the metadata of a small number of Tokens being mishandled. The team is working hard to restore the correct images and metadata.

"Block reorganization" occurs when the blockchain generates blocks at the same time. If there is an error or due to malicious attacks, it will cause a temporary duplicate blockchain. A "block reorganization" occurs because miners who add to the next block must decide which side of the fork is the correct chain or the canonical chain. Once miners choose to fork or canonicalize a chain, the other chain is lost.

Looking back at the last major "block reorganization" situation was on May 25, 2023, the Ethereum Beacon chain underwent a seven-block reorganization, exposing an advanced security risk known as chain reorganization. Validators on the Eth 2 (now consensus layer upgrade) Beacon chain became out of sync after a client update promoted a particular client.

"Collision" is actually not uncommon

Money.lens (@dotmoney), the founder of cryptochasersco, could not agree with the reply given by Azuki co-founder 2 PMFLOW that "the collision situation is due to the reorganization of the Ethereum block, which is a technical failure". He put forward his own opinion on social media. Opinion: The reason for the image collision is that the server listened to the event and did not handle the exception properly, not the data provider. The implication is that Azuki's map collision situation is a technical failure, which seems to be self-consistent.

When discussing the technical principle of NFT image generation, we need to pay attention to three core elements: layer style, generation algorithm, and the upload form of the generated NFT image. Due to the variability of these three factors, countless forms of NFTs can be produced.

First, layers can be viewed as pre-made assets, eg: 10 different colored backgrounds, 10 different hairstyles, 10 different hats, 10 different handheld parts, etc., all in their own right layers. Once the number and style of layers are determined, we can preset various influencing factors such as the rarity index, the number of images generated by the target, and thus create a set of NFT algorithms that can generate various combinations. Then, according to the generation algorithm, each material layer is superimposed from bottom to top to form a complete NFT.

According to the number of layers prepared in advance by the project party and the complexity of the algorithm, the probability of collisions in the generated NFT is also different. For example, when an NFT project party only prepares 3 layers, each layer has only more than 10 elements, and the generation algorithm is relatively simple, then the probability of collisions in the NFT series will be very high. However, for a blue-chip project like Azuki with multiple layers and hundreds of elements, and the generation algorithm is extremely complex, even if tens of thousands of new NFTs are generated, it is difficult for the image to collide.

Of course, because the process of image generation is completed off-chain, even if there is a collision phenomenon, a second screening can be performed on the image before it is officially uploaded to the chain to filter out duplicate images. This requires the project party to fully screen the generated NFT images before uploading them to the chain. Even if the project party directly generates the original material, it should have a reasonable screening process to ensure the performance of the program and all The combinations strictly follow the preset probability distribution.

So to sum up, where is the problem with Elementals?

First and most obviously, Elements is likely to directly apply the layers and elements of Azuki or BeanZ or even the generation algorithm. However, perhaps because the main body of this series of NFTs revolves around limited "element concepts" such as water, fire, and electricity, the relevant generation algorithms have not been debugged in place, resulting in repeated generation of NFTs.

Secondly, the community's statement that "the same picture is Mint in the same block" does not seem to be fully established. According to an NFT technician, the NFTs with collisions in the Elementals series do not have front-to-back or similar sequence numbers, indicating that they are less likely to be minted in the same block. Therefore, there is another explanation, that is, the Azuki team did not perform secondary screening on the generated Elementals, resulting in duplicate pictures being directly transmitted to the chain.

Of course, no matter what the reason is, it is unacceptable for a blue-chip NFT project party like Azuki to have a collision incident. It's clear that the team wasn't fully prepared for the Elementals launch.

Changing pictures under the nose, why can the pictures on the chain be modified?

In response to the issue of Elementals casting and drawing, Azuki co-founder 2 PMFLOW replied to the community on social media that the same image appeared for Elementals opening, saying that the team is working hard to restore the correct image and metadata. Then BlockBeats also found that when querying the Elementals series of contracts, the tokenURL of some NFTs could no longer display the query results. At the same time, some NFT previews of the Elementals series cannot be displayed normally on NFT trading platforms such as Blur. In this way, the Azuki team came to a real-time "picture-changing live broadcast" in front of the community.

Why can NFTs that have been uploaded to the chain and minted can be replaced and modified? This requires a brief review of how NFT images are stored.

We know that today's Internet is built on the HTTP protocol, which is a transmission protocol for transmitting hypertext from a web server to a local browser. When we fetch a web page or file via HTTP, we request and get information from the server. This is a centralized process, and there are many problems. For example, if the server fails, the file will not be accessible; at the same time, if a large number of users try to access a file at the same time, it will put a great pressure on the server bandwidth.

In contrast, IPFS takes a more distributed approach. IPFS is a protocol and network designed to create persistent and distributed storage and shared files. It is a new hypermedia transmission protocol that addresses massive data storage and bandwidth issues. IPFS stores files and other data as blocks on multiple nodes and uses a unique hash to identify each block. When a user requests a file, IPFS will fetch blocks from the closest node, not from the origin server. This makes data access faster and more stable, and will not cause data inaccessibility due to a single server failure.

Because of these advantages, IPFS has become the ideal choice and the largest consensus for storing NFT metadata today. The information contained in the NFT usually includes some description about the artwork, such as its author, creation date, etc. This information is called metadata. Due to the immutability of NFT, metadata needs to be stored permanently, and the distributed nature of IPFS can just provide such a service. At the same time, the distributed nature of IPFS can also prevent the metadata of NFT from being tampered with, ensuring the security of NFT.

In the IPFS file system, each file will generate a hash value based on the content, and the files in IPFS will be indexed based on this hash value. And check in advance whether the hash value has been stored. If it has been stored, it can be read directly from other nodes without repeated storage, which saves space in a certain sense. This greatly improves the efficiency of resource storage and reduces transaction costs.

After querying the contracts of the Elementals series, we found that the image metadata of Elementals was not uploaded to IPFS, but was stored in Azuki's own centralized server. Therefore, the ownership and modification rights of the metadata are in the hands of the Azuki team, and changes can be made at any time.

In fact, Elementals is not the only project that chooses to store pictures in its own server. Many "rich" blue-chip NFTs will do this to gain greater control over the project. But compared with Elementals, the metadata of the previous Azuki series is stored on IPFS. Then why did the team "backtrack" on the project's decentralization process? Perhaps everyone realized from the beginning that Elementals might have problems.

And what is even more outrageous is that the team made new mistakes in the process of modifying metadata. money.lens also found that the repair metadata uploaded by the Azuki team seems to be a file file, so it jumps to the download interface as soon as it is accessed. In other words, the server did not upload the normal json meta code, but directly uploaded the image file. Therefore, when a third-party trading platform such as Blur cannot read NFT image data on the server normally, the problem presented at the beginning of this paragraph occurs.

And when we look at the downloaded file pointed to by the metadata, we find that these new images can't even use the word "fixed" to describe it. Take Elementals #16580 as an example. As of writing, the metadata file of this NFT is not the same as the original version (see image below). Although the team has previously announced its own picture change action, such a big difference may be somewhat unacceptable to many people.

No matter how you look at it, the Elementals launch was a catastrophic event. It hit not only the Azuki community itself, but also the entire avatar NFT field. From experience, people's confidence and trust in NFT project parties are often very fragile, and Azuki's vampire behavior is rapidly consuming the remaining faith in this industry.

Of course, in the face of doubts and criticisms from the community, the Azuki team also responded positively, saying that they will work hard to make up for their mistakes, and announced a new "Mung Bean" airdrop this afternoon. As chaotic as the Elementals scene was, maybe we could save some faith and give Team Azuki one last chance?