Announcing the DeFi MOOC 2021 NFT and badge collection

5 min readJul 20, 2022

In August of 2021, we presented the first lecture of our Massive Open Online Course (MOOC) on Decentralized Finance (DeFi). Since then, the course has attracted many thousands of students participating from over 30 countries all over the world and currently with more than 170K lecture views. We appreciate your journey with us and all the positive feedback that has helped us improve the class.

As a way to commemorate the completion of this course, we are pleased to present the DeFi MOOC 2021 NFT collection. Given privacy considerations and the desire to have both a tradable NFT and a non-tradable certificate, the DeFi MOOC team will issue certificate badges in addition to the DeFi MOOC NFT using a privacy-enhancing solution supported by MetaMirror on the Oasis Network.

Each qualified student will be given both a tradable NFT and a non-tradable badge. We will have four tiers for the NFTs and will distribute NFTs in accordance with the rules on the MOOC’s website ( To claim your DeFi MOOC NFT and badge, please follow the instructions below.


Before 1st August, 2022:

  • Step 1 — Provide us the UUID using the Google form that was sent to your email. If you have not received the form, please check your spam folder and contact us at

After 2nd August, 2022, before 10th August, 2022:

  • Step 2 — Go to MBuddy Space(
  • Step 3 — Connect your MetaMask wallet. Note that Metamask will ask your permission to add the Oasis Emerald Mainnet network.
  • Step 4 — Click your wallet address on the top right corner, then click “Generate MBuddy”.
  • Step 5 — Navigate to the MBuddy generation page. Check the two boxes to confirm that you have read and understand the terms of use and the privacy policy for Auth3 Network. Click “Upload and Generate”.
  • Step 6 — Sign the message in MetaMask wallet to login your Parcel account.
  • Step 7 — After that, input your UUID (submitted in Step-1) as the credential ID in the pop-up window and click “verify” (If you skip this step, you will not get the correct MBuddy identity).
  • Step 8 — Once completed, check your MBuddy identity in DeFi MOOC MBuddy Space. Click your wallet address on the top right corner and you will see an identity badge labeled “Fall 2021 Class Tier” appears (link). This badge’s value should indicate your tier.

After 10th August, 2022:

NFT design

The design samples for our NFT collection are displayed in the image that can be found below. Dawn Song, Christine Parlour (University of California, Berkeley), Dan Boneh (Stanford), Andrew Miller (University of Illinois Urbana-Champaign), and Arthur Gervais (Imperial College London) are the lead instructors for this course. Because of this, the design of the NFT draws its influence from the landmarks of these four universities. The NFTs’ color (Bronze, Silver, Gold, Diamond) corresponds to the tier (Trailblazer, Ninja, Legendary and Honorary). The olive branches that surround the NFT represent peace.

DeFi MOOC 2021 Sample NFTs

I am familiar with NFTs; but, what is the purpose of the badges?

We are fans of NFTs. However, if we were to issue our DeFi MOOC certificate of completion using NFTs, we would have to make it non-tradable in order to avoid trading certificates. To mitigate the above issue, in addition to the NFT, we will issue a non-transferrable certificate (i.e., the badge) to each qualified student. I will leave the technical details to the next section, but at a high-level, we (i.e., DeFi MOOC team, MBuddy and MetaMirror) will not be able to see the mapping between your wallet address and email address when distributing the NFTs and badges.

Why do I need to submit a UUID?

In our current implementation, the DeFi MOOC team will be able to see the UUIDs collected via Google Forms and will upload the collected UUIDs and corresponding tier to Parcel, a privacy-preserving data governance solution on Oasis platform. Qualified students can then use MetaMirror to link the UUIDs (and thus the corresponding tier) to their wallet addresses. This linking process takes place within the Parcel Runtime, which is run inside secure enclaves (TEEs) and thus not accessible to anyone, including the DeFi MOOC team and the MetaMirror team. In the future, we will support zkp-based anonymous credentials instead of manually generated UUIDs.

Technical implementation

The DeFi MOOC collection makes use of MetaMirror, a privacy-enhancing technology, in order to protect the data privacy of its users. Since wallets and credentials are mapped inside the Parcel environment, the DeFi MOOC team will not be able to match an individual student’s email address to its wallet address. In more detail:

Parcel: Parcel Runtime offers a collection of APIs that put an emphasis on users’ data privacy. The data that is uploaded to Parcel is encrypted. This data can be taken as an input by programs, which will then execute in a confidential computing environment before storing the results back in Parcel.

User Data: We will require each user to provide the DeFi MOOC team with a randomly generated UUID string, which we will refer to as the credential ID. MetaMirror will assist users in storing the credential ID in the appropriate Parcel account.

Wallet Address: No one can see the mapping between the users’ wallet addresses and the credential IDs (including MetaMirror and the DeFi MOOC team). Such mapping will be directly uploaded to each user’s Parcel account and be protected with TEE (Trusted Execution Environment) technology. MetaMirror’s algorithm will run inside Parcel to access such mapping to issue NFTs and badges, and Parcel enforces the privacy of the mapping using TEE.

MBuddy Attributes: MetaMirror calculates the DeFi MOOC’s certification attribute (e.g., Honorary, Legendary, Ninja, and Trailblazer tiers) in Parcel, based on the users’ credential ID. After the execution, Parcel will sign the result, to prove that the MBuddy attribute is calculated in Parcel. Meanwhile, MetaMirror also implants a private key in Parcel to sign the calculated MBuddy attribute, to prove that the attribute is calculated by MBuddy’s attribute generation algorithm.

NFT Distributions: By leveraging MetaMirror MBuddy, the DeFi MOOC team can retrieve a set of wallet address-and-attribute mappings. After that, the MetaMirror team will “airdrop” (also known as “batch mint”) the NFTs correspondingly to each of the wallet addresses, which means the users will not be required to pay any cost. The DeFi MOOC NFTs are compliant with the ERC-721 standard, and they can be viewed in any of the NFT markets that are compatible with the Oasis blockchain (e.g.,

Note that the wallet addresses in each tier forms an anonymity set, similar to most of the mixers such as We do recommend using new addresses because it enhances privacy and makes it more difficult to link accounts.

Looking forward

DeFi is still in its nascent stage, and interests in the course continue to grow. We will run this course again in Fall 2022. Please help spread the words by referring people to the course website (