Introduction to Digital and Privacy-Preserving Signatures

Introduction to Digital and Privacy-Preserving Signatures

Digital signatures are a basic cryptographic building block that ensures messages' authenticity (who signed) and integrity (what is signed).
The goal of this proseminar is to improve students' presentation skills and, at the same time, learn about digital signatures and schemes
that relax the above properties to increase the privacy of signers. We will discuss seminal research papers introducing, among others:
Ring signatures, group signatures, and blind signatures.

Each week two students will present their assigned paper, followed by a group discussion about the presentation and the article
(it is highly encouraged that all students have read the article). After the first round, there will be a second round where students
will present their improved presentation, and only the second round will be graded.

Logistics

Time: Thursdays 8:15-10
 

Venue

Campus E9 1 (CISPA C0 building), lecture hall
 

Instructor

Lucjan Hanzlik (lucjan.hanzlik@cispa.de)

 

Timeline
 

Date	Topic
Phase 1
16.11.2023	A method for obtaining digital signatures and public-key cryptosystems
23.11.2023	Short Signatures from the Weil Pairing
	Constructing Digital Signatures from a One Way Function
30.11.2023	How to Leak a Secret
	Foundations of Group Signatures: Formal Definitions, Simplified Requirements, and a Construction Based on General Assumptions
7.12.2023	Blind Signatures for Untraceable Payments
	Domain-Specific Pseudonymous Signatures for the German Identity Card.
14.12.2023	Structure-Preserving Signatures on Equivalence Classes and Constant-Size Anonymous Credentials.
	Generalized Channels from Limited Blockchain Scripts and Adaptor Signatures
Phase 2
11.01.2024	A method for obtaining digital signatures and public-key cryptosystems
25.01.2024	Short Signatures from the Weil Pairing
	Constructing Digital Signatures from a One Way Function
01.02.2024	How to Leak a Secret
	Foundations of Group Signatures: Formal Definitions, Simplified Requirements, and a Construction Based on General Assumptions
08.02.2024	Blind Signatures for Untraceable Payments
	Domain-Specific Pseudonymous Signatures for the German Identity Card.
15.02.2024	Structure-Preserving Signatures on Equivalence Classes and Constant-Size Anonymous Credentials.
	Generalized Channels from Limited Blockchain Scripts and Adaptor Signatures

 

Topics
 

Standard and Advanced Signatures

1. Rivest, Shamir, Adleman: A method for obtaining digital signatures and public-key cryptosystems (alternatively link1 and link2)
2. Lamport: Constructing Digital Signatures from a One Way Function
3. Boneh, Lynn, Shacham: Short Signatures from the Weil Pairing
4. Ducas, Kiltz, Lepoint, Lyubashevsky, Schwabe, Seiler, Stehlé: CRYSTALS-Dilithium: A Lattice-Based Digital Signature Scheme

Privacy-Preserving Signatures

5. Rivest, Shamir, Rivest: How to Leak a Secret
6. Bellare, Micciancio, Warinschi: Foundations of Group Signatures: Formal Definitions, Simplified Requirements, and a Construction Based on General Assumptions
7. Chaum, Fiat, Naor: Blind Signatures for Untraceable Payments (alternative link)  and Untraceable Electronic Cash (2 short papers on the same topic)
8. Bender, Dagdelen, Fischlin, Kügler: Domain-Specific Pseudonymous Signatures for the German Identity Card.
9. Fuchsbauer, Hanser, Slamanig: Structure-Preserving Signatures on Equivalence Classes and Constant-Size Anonymous Credentials.

Signatures in Cryptocurrencies

10. Boneh, Drijvers, Neven: Compact Multi-Signatures for Smaller Blockchains
11. Aumayr, Ersoy, Erwig, Faust, Hostakova, Maffei, Moreno-Sanchez, Riahi: Generalized Channels from Limited Blockchain Scripts and Adaptor Signatures
12. Thyagarajan, Malavolta: Lockable Signatures for Blockchains: Scriptless Scripts for All Signatures