A place to keep material/studies/resources for my thesis. Will share the updates on the progress here.
Oct 26
- ✔️
The request is still being processed (Thesis Topic Description)
Nov 30
- Uploaded the thesis registration form
- Proposed title: P2P Cooperative System to combat double spending with Lattice-based blind signatures
Dec 13
- 🍀 The Thesis Topic Description request was approved!
Mar 26, 2024
- ✍️ Broad categories are Digital Signatures, Blind Signatures, Lattice-based Signatures followed by the solution I want to implement.
- 😅 Have to step up the game
Apr 03, 2024
- Work on the text for ROS problem
- Finish the first two sections this week - Digital Signatures and Blind Signatures
Apr 22, 2024
- I should be working on writing the thesis now ✍️ on it!
- Should be completed with the major text by end of May
June 11, 2024
- Preparing for the presentation!📺
June 28, 2024
- Completed the thesis defense succesfully! 🎂
Central bank digital currency (CBDC) is money that a country's central bank can issue. It is also referred to as e-cash. One of the major problems with e-cash is double-spending or double-use. As compared to users connected to an online trusted-third-party, offline users cannot verify if e-cash is already spent or not. More specifically, in a buyer-merchant setting, it is difficult to detect double-spending of a payment if a bank/broker service is not available.
[1] combats this using cooperative P2P Systems where merchant(s) can be a witness to verify a payment. It assumes the hardness of discrete-log problem and uses blind signatures to blind(hide) private information. Besides being insecure in a post-quantum setting, this design is susceptible to sybil attack [2] where an entity may create fake-multiple identities to act as witnesses.
A study by VISA [3] tackles double spending in offline transaction by leveraging digital signatures generated by TEE (Trusted Execution Environment). This component is present in most mobile devices in secure hardware, which are hard to replicate and compromise.In my thesis, I will employ lattice-based blind signatures in the P2P cooperative system. This ensures security in the post-quantum setting. I will also investigate if TEE can be used to ensure authenticity of unique devices to protect the architecture from sybil attack.
[1] Combating Double-Spending Using Cooperative P2P Systems -https://people.cs.ksu.edu/~eyv/papers/ecash-icdcs07.pdf [2] Bitcoin and Beyond: A Technical Survey on Decentralized Digital Currencies - https://eprint.iacr.org/2015/464.pdf [3] Towards a Two-Tier Hierarchical Infrastructure: An Online Payment System for Central Bank Digital Currencies -https://arxiv.org/pdf/2012.08003.pdf
- Read the paper carefully
- Learn about Blind Signatures
- Learn about Lattice-based Blind Signatures
- How you can fit them into the original paper
- Security analysis
- How to use TEE/TPM to protect against Sybil attack - TPM - Microsoft