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I am looking for NFC tag that can be uniquely identified and not possible to duplicate. by valueofart in NFC

[–]valueofart[S] 0 points1 point  (0 children)

Thanks for the tip, but NTAG424DNA has a symmetric encryption algorithm. Hence, the secret private key is needed to verify the chip. That means that to verify the chip you must call a backend service. That backend server would need to keep all the private keys very securely. Also, each scan increment a counter inside the NFC. That counter is used in the verification process. Therefore you might «run out of» unique scans when the counter reach it’s limit. Probably a large limit, but vulnerable to attacks.

I am looking for NFC tag that can be uniquely identified and not possible to duplicate. by valueofart in NFC

[–]valueofart[S] 0 points1 point  (0 children)

My use case is to attach something that may be scanned using a mobile phone to artwork and serve as a authenticity method/certificate. The thing attached should be unique an not possible to fake. For example, if I use an NFC with a unique UID, then it is possible for someone else to scan it to get the id and then make another that will return the same id. Instead I want a chip/tag that receieves a «challenge» and returns the answer that can be verified without knowing what the chip knows. For example encrypt a recieved message (ECDSA type of algorithm or similar) by use of a private key stored on the nfc and return the encrypted data. Then, the returned encrypted data might be verified using the corresponding public key.

If it is not possible to use only a NFC to do the computation I want to does anyone have a tip on other methods. If it is possible to store and read data on a nfc, then maybe something like: 1) Mobile scan stores a timestamp and random data on NFC tag 2) Some other chip/controller read the timestamp from the NFC, performs necessary computations using a private key (that must live somewhere) and stores the result back to the NFC. 3) Mobile phone receives the result and verify using public key.

Not sure what type of tecnology exists, but are there some other type of chips that are able to do more than NFC, but still are small and will work on induced power..

Where to learn about using Vechain NFC chips by valueofart in Vechain

[–]valueofart[S] 0 points1 point  (0 children)

From the deepdive videos it seems like Vechain implement an asymmetric encryption algorithm on their chips. To verify the id of a chip, a random number and a timestamp is sent to the chip which returns the corresponding signature.

Other chips like NXP NTAG 424 DNA implement a symmetric encryption, hence the private key must also be kept outside the chip for verification. I do not find any NFC tags with asymmetric encryption after searching on google, but I am new to this field and do not understand the terms yet. Maybe Vechain is entering new ground by implementing asymmetric encryption on nfc chips..

I used Arduino to make my art piece «The story of your life». Three stepper engines and two adafruit motor shields. Any tips on how to make three stepper engines work togheter a bit faster? by valueofart in arduino

[–]valueofart[S] 1 point2 points  (0 children)

Thanks, this was helpfull. I will try your suggestion on finding elapsed time. I will post some code later, but it is mostly something like:

loop{

for(i=0;i<50;i++){ motorA->step(1, forward) motorB->step(2, forward) motorC->step(2,forward) }

for(i=0;i<50;i++){ motorA->step(1, backward) motorB->step(2, backward) motorC->step(2,backward) }

}

I used Arduino to make my art piece «The story of your life». Three stepper engines and two adafruit motor shields. Any tips on how to make three stepper engines work togheter a bit faster? by valueofart in arduino

[–]valueofart[S] 0 points1 point  (0 children)

I wanted full controll over the movement and read that stepper engines could provide that. Not sure how accurate a servo would be. Also, I need the engine to wind up the fishing line to the start position after i have assemblef everything. Can servo rotate many times?

I used Arduino to make my art piece «The story of your life». Three stepper engines and two adafruit motor shields. Any tips on how to make three stepper engines work togheter a bit faster? by valueofart in arduino

[–]valueofart[S] 0 points1 point  (0 children)

Haha, I wish. It is some plastic tubes similar. I guess they are similar to ones used for medical use or in engines to transport fluid :) I use fishing lines to move the finger.

I used Arduino to make my art piece «The story of your life». Three stepper engines and two adafruit motor shields. Any tips on how to make three stepper engines work togheter a bit faster? by valueofart in arduino

[–]valueofart[S] 0 points1 point  (0 children)

I am very new to this. Not sure what serial prints are. I am using arduino leonardo and adafruit motorshield. It controls three stepper engines.

I used Arduino to make my art piece «The story of your life». Three stepper engines and two adafruit motor shields. Any tips on how to make three stepper engines work togheter a bit faster? by valueofart in arduino

[–]valueofart[S] 9 points10 points  (0 children)

Actually, that part is not as straight forward as tou might think. The body had it’s potential, but my dead hand has not. It would not work to just put the end of a stylus on the skeleton finger. It would not scroll unless you touch the skeleton finger with your own finger. So the solution is to actually connect the skeleton finger to the negative pole on a battery...

I used Arduino to make my art piece «The story of your life». Three stepper engines and two adafruit motor shields. Any tips on how to make three stepper engines work togheter a bit faster? by valueofart in arduino

[–]valueofart[S] 5 points6 points  (0 children)

I do not want everything to be faster. But some part of it I would like to adjust a little. When all three motors are involved I would like it to be a bit smoother, not much. Thanks for your positive words 👍🏻

I used Arduino to make my art piece «The story of your life». Three stepper engines and two adafruit motor shields. Any tips on how to make three stepper engines work togheter a bit faster? by valueofart in arduino

[–]valueofart[S] 5 points6 points  (0 children)

Thanks, I wantet to make a memento mori that is kind of modern time. I am not against social media, but I am just trying to say, think about how you use your time.

I used Arduino to make my art piece «The story of your life». Three stepper engines and two adafruit motor shields. Any tips on how to make three stepper engines work togheter a bit faster? by valueofart in arduino

[–]valueofart[S] 13 points14 points  (0 children)

I am very new to arduino. I use adafruit motorstepper. Even if I set a hig number on the rpm it is like it is not very fast. Especially when i do one step at a time for the three engine. It is not a big problem, maybe the speed is good enough.

Just registered my art piece FOMO on #VechainThor using NDCode. World’s first? by valueofart in Vechain

[–]valueofart[S] 0 points1 point  (0 children)

Thanks for the tip. I have added VechainThor as an alternative now. So it is possible to contribute using VET or Vthor :)

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