from creating another NFT representing the same image. They can be placed in the same collection, as well as across multiple collections.Īs NFTs basically contain links to this image, it's not possible to prevent someone from creating a link to a public resource, i.e. It is technically possible to create multiple NFTs that all represent the same image. Here is a sample code for UI (JavaScript and HTML):Ĭould NFT be created from the same image or copy of this image?Ĭan someone download the image and create an NFT from it?

If not, we know that the nonce was not signed by the Metamask wallet we expected. Generate the JWT and respond to the client. If it matches, then we have a positive match.

Check if any of the generated keys match public wallet ID that the client sent.

At max, one will be able to generate 4 possible public keys for this message.

Using the ECDSA Signature and Hash of the Nonce, generate the possible public Key that was used to sign the message.

R and S are the outputs of the ECDSA Signature and V is the Recovery ID. This basically retrieves the V, R and S and.

Generate the signature data from the message.

Retrieve the nonce sent to the client with the same wallet ID.

Receive the signed message and the wallet ID from the client.

Rather I needed to use the nonce to see if I can retrieve the public key of the private key used to sign the message and see if that public key retrieved matches the wallet ID. I was not supposed to attempt to decrypt the message to retrieve the nonce. Here is my code to create and send the nonce to UI: According to this, I would need to 'decrypt' the message using the public key and see if the decrypted message is same as the nonce that the backend sent to Metamask to sign. My understanding is that the public key is the wallet ID itself and that the message is the nonce signed by the private key of the wallet which is not shared for obvious reasons. Is web3j not the right package to use for this? The example shows how to do the verification on NodeJS based on javascript but I don't find any example on how to do this on Java. However, I am unable to find any documentation on Web3J to do this. I am trying to verify the signed nonce from the Wallet on the server to make sure that the sender is indeed who they say they are.

I am able to autogenerate the nonce and receive the wallet ID without a problem. I am trying to connect my Metamask wallet to my Java Spring-Boot backend. configure -enable-dualminer -enable-scrypt -disable-opencl -prefix=$dir_path/ make & make install may be you need to use sudo for more permissions. compiling for linux(ubuntu10 version or higher). the following will show how to compile the dualminer-cgminer. paying more attention to, new miner will be upcoming ,higher hash force use less power. the dualminer usb is the world's first asic based usb miner for both sha-256 and can be setup to mine litecoin only, or bitcoin and litecoin simultaneously. you can miner litecoin or bitcoin by dualminer usb. if you encounter an error ,you can submit to us through your comments and suggestions are welcome.

and they will be fixed in the near future. the first verison of dualminer-cgminer ,is under debugging, so there maybe some errors and bugs. or the flowing sections will tell you how to make the dualminer-cgminer and run it. you can dualminer support websit(to know how to make your dm3/dm2/dm1 work effcicently use dualminer-cgminer. certainly, on windows and linux such as ubuntu,it also run well. You can download it from GitHub.ĭualminer-cgminer is asic miner for both sha-256 and scrypt ,it is cgminer-3.5.0-based development,had a large number of test on raspberry pi and beagleboard. dualminer-cgminer has no bugs, it has no vulnerabilities, it has a Strong Copyleft License and it has low support. Dualminer-cgminer is a C library typically used in Blockchain, Cryptocurrency, Bitcoin applications.

Cgminer 3.5.0 windows