Signatures 2
summary
Proposes an ABS scheme that adds delegation of policy by splitting message and policy commitments, proving security by extending Okamoto–Takashima’s indexing to three dimensions, and enabling tracing that traces to first delegator only while keeping signature size linear in policy rather than delegation history. Separately builds a lattice-based TAPS using dual Regev encryption, Fiat‑Shamir‑with‑abort ATS from SIS/LWE, a lattice zero‑knowledge threshold proof for T‑of‑N, gives 128‑bit parameters and practical signature sizes, and notes proofs work but tracing granularity and proof size remain trade‑offs.
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chapters (17)
- 0:00Attribute-based signatures intro
- 3:15Attribute-based signatures basics
- 8:17Delegation motivation in ABS
- 13:40Traditional delegation challenges
- 15:04Delegation of policy
- 18:45Meeting ABS needs
- 19:05Proposed solution overview
- 23:44Lattice-based TAPS intro
- 27:02Threshold accountable private signatures
- 32:53Lattice assumptions for TAPS
- 34:19Lattice-based signature design
- 37:20Signing protocol modification
- 41:52TAPS from ATS signature
- 42:19TAPS threshold proof
- 43:32TAPS performance comparison
- 44:16Conclusion and future work
- 45:38Q&A
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