Let’s register the most original NFT on the Crown blockchain!

Bounties worth 8500 CRW ($425) waiting for the top 3 winners.

Crown Platform


In order to drive visibility and use of the recently released Non-fungible tokens (NFT) Framework which enables public and private participants to tokenise assets on the Crown blockchain, the community has launched a bounty contest with the following details and rules:

Goal: Register the most original NFT on Crown.

NFT Form: Picture, crypto art, video, any ORIGINAL visual or text form.


1.Register your NFT (a simple guide of the steps is below)
2. Share your visual output and NFT txid in Twitter via a Tweet tagging @crownplatform

Voting: The Crown community will vote and select top 3 visuals in the CRW Telegram and Discord channel poll. Votes in both channels will be counted together.


Winning prize: 5k CRW (approx 250 USD)

2nd prize: 2.5k CRW (approx 125 USD)

3rd prize 1k CRW (approx 50 USD)

Contest duration:
* NFTs must be registered and tweeted before 22:00 CEST on Sunday May 10th, 2020.
* Votes must be cast by 22:00 CEST on Sunday May 17th, 2020

For those learning how to use the CRW NFT registration tool, we have put together this short guide. For the competition you need to prepare your content, collect the information needed for the NFT and finally create it.

1. Create your original content.

It’s entirely up to you what you create and how.

2. Digitise it if it’s not already in digital format.

For example, a sketch or painting could be digitised with a scanner or a photo on your mobile phone.

3. Create a sha256 checksum of the digital representation.

Blockchains are not good places to store actual content (a single photo could be several MB, a video hundreds of MB) so we use a sha256 checksum as a short form representation.

Linux users

You can easily create a sha256sum from the command line or perhaps from your file manager. If your content is called /home/alice/art/crown1.tiff you could use the command
sha256sum /home/alice/art/crown1.tiff
to generate the checksum

Mac users

If your content is called /users/bob/crownpic.png you could use the command
shasum -a 256 /users/bob/crownpic.png

Windows users

You may already have a command line or GUI tool installed. If not there are lots of possibilities, some suggestions are here. If your content is called C:\Desktop\photos\competition.mp4 you could use the command
certutil -hashfile C:\Desktop\photos\competition.mp4 SHA256

4. Host the digital representation on any publicly accessible URL.

Use any cloud platform, blog or website you have access to. If you’re using Dropbox, Google Drive, Mega etc., please set the sharing options so that the URL is publicly accessible. Use a URL shortener if you want to pay the smallest possible NFT transaction fee.

Please also ensure the content you upload is the exact one you created the checksum from. It’s a good idea to download the content yourself, calculate the checksum again and compare it with the original value. Some sites, for example imgur.com, alter the content slightly. If the checksum we calculate of the object found at your URL (stored in the metadata field of the NFT) doesn’t match the value in the token id your entry may be invalidated.

5. Prepare to create your NFT.

You will need to provide the following information for your token:
* sha256 checksum as created above. This will be your token id, referred to as <token_id> below.
* Crown address to own the token (any address from your wallet), referred to as <token_address> below.
* URL of the digital representation, referred to as <token_meta> below.

6. Create your competition token

We have created an NFT protocol called nftcomp for competition entries.

You can use the crown-cli tool or the debug console in the GUI wallet to actually register the token using the following steps:

  • unlock your wallet
    {crown-cli} walletpassphrase “your password here” 300
  • generate a new address if required
    {crown-cli} getnewaddress “competition”
  • register the NFT
    {crown-cli} nftoken register nftcomp <token_id> <token_addr> 0 <token_meta>
    Successful registration will emit the transaction id you need for your tweet. Registration failure will produce an error message. If the message is
    error: {“code”:-32603,”message”:”Signing transaction failed”}
    then you forgot to unlock your wallet. If you can’t resolve any other problem please contact us in the #support-wallet channel in Discord.

Don’t forget to tweet your competition entry, for example
@CrownPlatform I just registered #CompetitionEntry #NFT 9bd7bd1b35e66120391959fc7af01aaf3b445703d8660629f310470bd42633a8 representing http://bit.ly/3byUfmm on the $CRW Crown blockchain

You can view competition entries in the dedicated page of the Crown Platform Monitor.
You can view all the other registered protocols and tokens in the monitor too. On the NFTs page you could use the competition protocol name (nftcomp) in the search box or use the “Same protocol” option in the dropdown box on any nftcomp token. Then use the “Txn details” option to see the raw transaction including the metadata which contains the entry URL.