Proof of Scan consensus. How does that work?

6 min readJan 14


Proof of Scan is a revolutionary decentralized protocol, which is leveraged not only as 3DPass blockchain network consensus, but also designed to prevent digital assets from copying. All of those assets present nothing, but endless of kinds of objects tokenized, such as: 3D objects, 2D drawings, melodies, voices, radio signals, and so on. Due to the recognition technology the protocol is based on, this novel approach unfolds the access to potential trillions in deals all over the globe.

Let’s have a look “from helicopter” to figure it out how does that work as well as how useful could it be for dApp developers. Apparently, the easiest way to do that is to compare PoScan (Proof of Scan) with PoW (Proof of Work) the crypto community got to learn about the most.

“One object = One asset” rule

The first and the most important PoScan (Proof of Scan) rule states “1 object = 1 asset”, which refers to the recognition algorithm being used instead of some usual hash function like SHA256. As such, Grid2d algorithm is leveraged for 3D object recognition in 3DPass.

one object = one asset



any text or file — > SHA256 — > a hash inherent to the exact text or file

  • The chain from an object to its SHA256 hash is broken. SHA256 hash doesn’t have to do with anything real or representing value.
SHA256 hashing
  • The SHA256 hash will remain the same, if the text or file is the same. Had you changed the file or text with one symbol or one byte, the output would have changed dramatically, even though it was still the same object (a picture with the same image on it, the same 3D model with just one dot on the surface, the same piece of music with 1 sec plus, etc). SHA256 has no control over the object’s copies, it does know nothing about its existence.
fake is impossible to recognize


3D model in .obj format -> Grid2d -> HASH ID (a list of hashes inherent to the object shape)

Grid2d recognition, HASH ID creation
  • The hashes will match, if the object shape is considered to be the same within the error of resolution, which is possible to set up by means of the recognition parameters. In other words, irrespective to how much dots you put on the surface, the HASH ID would still have matched until you damage the object shape enough.
fake is recognized

> In order to get some practice, everyone might play around 3D objects mined on 3Dpass with the mobile wallet.

It now becomes apparent, that using the recognition algorithm allows for authentication of nothing, but the object itself, whiles the regular hashing can only authenticate an exact text line or file. That is the crucial point to understand before scrolling down the text and learn something on top.

Mining and block seal

Talking simple, in usual PoW (Proof of Work) miners are picking up a value called “nonce” which, being added to the parent block hash, would make the hash function (ex. SHA256) produce a specific output (the hash value below the limit called “Difficulty”) like “0000000….”. So that every node on the network can verify the seal and proof the block authenticity, provided they use the same hashing function. Basically, it is guaranteed us to have the only unique block hashes correctly sealed together into Best chain (main chain of the blockchain).

In PoScan (Proof of Scan) 3D object is used as a “nonce”. And so, miners are guessing a unique-shaped 3D object the HASH ID of which, being sealed to the parent block hash with SHA256, would give the same result (“0000000….”). And all the nodes on the network can have both Grid2d and SHA256 to verify the authenticity of the block as well as the object. Learn more in the protocol description.

The Ledger of Unique Things

User’s objects, being tokenized and stored on 3DPass blockchain, will be verified by miners in the same way. This will guarantee the presence of only unique and original objects on the blockchain. All fakes are to be rejected, which means the asset copy protection. Because of this feature 3DPass blockchain presents itself as “The Ledger of Unique Things”.

Deterministic finality

In order for users to be sure that their assets tokenized are always sit on Best chain (the current main chain of the blockchain), meaning they can move them anytime, regardless to the mining competition, the deterministic finality is applied in PoScan (Proof of Scan) instead of probabilistic finality provided by conventional PoW (Proof of Work).

Thus, in classic PoW (Proof of Work) consensus (ex. Satoshi Nakamoto, which first was applied in Bitcoin) it is allowed for several legitimate chains to grow up simultaneously, the longest chain wins competition. Therefore, there’s always a chance for Best chain (the longest one) to be reorganized as a result of miners’ competition. This leads to the potential situations of losing control over the assets stored on the blocks happened to get in the fork and eventually ended up useless. These situations are out of user control on Bitcoin, Ethereum (PoW), etc.

probabilistic finality

PoScan (Proof of Scan) is equipped with GRANDPA deterministic finality PoA (Proof of Authority) protocol in addition. There is an Authority set called Validators consisting of the most reliable nodes originally selected from out of miners — authors produced at least one block in the 100–8000 most recent blocks looking back. They vote upon Best chain, and after all voting rounds are complete there will be no chance for the finalized chain to get reorganized (2/3 + 1 positive votes is enough to make the final decision).

deterministic finality

Validators are getting rewarded for their work as well as miners. New block rewards are split: 30% — Validators, 70% — Miners. This approach is kind of similar to either “Masternodes” or PoS (Proof of Stake). Both collateral and block authorship is required to head in Validator set, which makes selection threshold pretty high. Validators also have to follow the SLA (Service Level Agreement) to maintain in the set, getting slashed with penalties for misbehavior.

Scalability: “What could be recognized”

PoScan (Proof of Scan) design allows for number of recognition algorithms to work at the time. Grid2d is just the first one created specifically for 3D objects. The recognition lib is open to add new ones like 2D drawings, melodies, voices, radio signals, etc.

what could be recognized

Decentralized applications

By means of utilization of Proof of Scan protocol, game changing possibilities for dApp developers are getting uncovered. Once having an object tokenized, the asset’s owner gains full control over its copies without a middlemen.

Property rights borders are proved by math calculations and always defined by means of recognition parameters set up for each particular asset or group of assets. Multi object option makes assets useful even offline, providing zero knowledge about the actual object properties.

3D or 2D art creators could sell their work as copy protected non-fungible or fungible tokens tethered to art object identity (HASH ID). Music could be sold p2p by pieces, as well (one track = one asset).

Some real objects could be tokenized and turned into backed digital currency, ex. diamonds/carats. Objects could be converted into limited supply users’ assets in different games, VR/AR, Metaverse.

There are endless business scenarios to use, it’s all about creativity.

That’s it for basics! I hope you’ll enjoy 3DPass and create the best dApps ever!

Learn more details in the White Paper


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3Dpass is an open source Layer 1 decentralized blockchain platform for the tokenization of objects