Cross-Input Signature Aggregation (CISA) is a proposed upgrade to Bitcoin that could potentially enhance privacy and provide cost-savings for transactions. HRF is sponsoring a four-month research fellowship to help analyze the state and future of CISA. The product of the fellowship will be an industry paper that addresses the following:
1) How could CISA improve Bitcoin privacy?
2) Exactly how much cost-savings could CISA provide across different types of transactions? This will include a comparison of full versus half aggregate implementations.
3) How meaningful might these cost savings be to different industry participants? Given historical precedent, could these cost savings make Taproot the default script type, as Native Segwit is today?
4) Could CISA, if adopted widely, reduce the effectiveness of chain analysis?
5) Could CISA pave the way for cheaper transactions in a high-fee environment?
6) Could CISA lower the minimum economically spendable account at a given fee rate?
7) Could CISA help exchanges by, for example, saving them money while they consolidate small UTXOs?
8) How does CISA compare to other aggregation strategies?
9) Are there any ways in which CISA could help upgrade or complement the Lightning Network, eCash, or existing CoinJoin mechanisms?
10) How might CISA protect the social and legal choice of Bitcoin users and businesses to CoinJoin, and the likelihood of more CoinJoin behavior, if users could state (if asked) that their decision was based on saving money, not simply seeking more privacy?
11) How would Bitcoin Core need to change to integrate CISA? Are there any known current improvement proposals?
12) How would SegWit need to change to integrate CISA?
13) Could CISA be packaged with (and might it be mutually beneficial with) any existing softfork convent proposals?
14) Would CISA have any impact on output destruction versus creation? How would implementation relate to the witness discount?
15) How problematic would the interactive nature of full aggregate CISA be? What strategies might be adopted to ameliorate this?
16) What would be the main downsides and risks of bringing CISA to Bitcoin?
17) How would a CISA-powered for-profit service that could help people save money on fees, if they are willing to enter an interactive pool, work?
18) What other kinds of CISA-powered apps can be envisioned?
The fellowship is being created with the acknowledgement that CISA may not be a helpful or appropriate addition to Bitcoin, but with the open mind that it might be.
The fellow will receive 50 million satoshis to support their efforts during the research and writing period.
The research is expected to be on par with the standards established by bitcoinrollups.org, a previous HRF research fellowship reviewing Bitcoin rollup technology.
To apply, please email [email protected]. Please include relevant information about your industry or academic background, a research plan in terms of who you will speak to, and your current sense of the impact CISA could have for Bitcoin. Applications will be accepted until May 15, 2024.