Abstract
The universal composability (UC) model provides strong security guarantees for protocols used in arbitrary contexts. While these guarantees are highly desirable, in practice, schemes with a standalone proof of security, such as the Groth16 proof system, are preferred. This is because UC security typically comes with undesirable overhead, sometimes making UC-secure schemes significantly less efficient than their standalone counterparts.
We establish the UC security of Groth16 without any significant overhead. In the spirit of global random oracles, we design a global (restricted) observable generic group functionality that models a natural notion of observability: computations that trace back to group elements derived from generators of other sessions are observable. This notion turns out to be surprisingly subtle to formalize. We provide a general framework for proving protocols secure in the presence of global generic groups, which we then apply to Groth16.
We establish the UC security of Groth16 without any significant overhead. In the spirit of global random oracles, we design a global (restricted) observable generic group functionality that models a natural notion of observability: computations that trace back to group elements derived from generators of other sessions are observable. This notion turns out to be surprisingly subtle to formalize. We provide a general framework for proving protocols secure in the presence of global generic groups, which we then apply to Groth16.
| Original language | English |
|---|---|
| Title of host publication | Theory of Cryptography |
| Subtitle of host publication | 22nd International Conference, TCC 2024, Milan, Italy, December 2–6, 2024, Proceedings, Part I |
| Publisher | Springer |
| Pages | 90-124 |
| Number of pages | 35 |
| ISBN (Electronic) | 9783031780110 |
| ISBN (Print) | 9783031780103 |
| DOIs | |
| Publication status | Published - 2 Dec 2024 |
| Event | Theory of Cryptography Conference: 22nd International Conference - Milan, Italy Duration: 2 Dec 2024 → 6 Dec 2024 Conference number: 22 https://tcc.iacr.org/2024/ |
Publication series
| Name | Lecture Notes in Computer Science |
|---|---|
| Publisher | Springer |
| Volume | 15364 |
| ISSN (Print) | 0302-9743 |
| ISSN (Electronic) | 1611-3349 |
Conference
| Conference | Theory of Cryptography Conference |
|---|---|
| Abbreviated title | TCC 2024 |
| Country/Territory | Italy |
| City | Milan |
| Period | 2/12/24 → 6/12/24 |
| Internet address |