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Distributed Identity Based Short Linkable Ring Signature
Kasra EdalatNejad
- Prof. Bryan Ford
DEcentralized and DIstributed Systems
Goal
- Anonymity
- Accountability
- Usability
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Distributed Identity Based Short Linkable Ring Signature Kasra - - PowerPoint PPT Presentation
Distributed Identity Based Short Linkable Ring Signature Kasra - - PowerPoint PPT Presentation
Distributed Identity Based Short Linkable Ring Signature Kasra EdalatNejad Prof. Bryan Ford DEcentralized and DIstributed Systems Goal Anonymity Accountability Usability 2 Ring Signature Anonymous Spontaneous 3 Linkable Ring
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Ring Signature
Anonymous Spontaneous
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Linkable Ring Signature
- Event tag
- Accountable
- Linear size
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Cryptographic Accumulator
- Make a short representation
- Not a compresion
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Accumulator
- Accumulate set(X): V
- Generate witness: W
- Check membership: (x, W, V)
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Additional properties
- Dynamic
- Authority
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Bilinear Pairing (Nguyen)
- Master Secret Key: s
- Publicly computable
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Bilinear Pairing (Nguyen)
- With Authority:
○ Dynamic ○ Authority
- No Authority:
○ Trusted setup ○ Not efficient
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Accumulator Ring Signature VS
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Short Linkable Ring Signature
- Membership in ring
- Knowing private key
- Correct link tag
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Identity Based Cryptography
- Public key is based on name
- No Certificate Authority
- Authority generate private key
- Key escrow
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Bilinear pairing SLRS
- Membership: Nguyen’s Accumulator
- Knowledge of private key:
○ Sakai-Kasahara IBC ○
- Link
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Secret Sharing: Direct
- Shamir polynomial
- Distributed key generation
- Compute:
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Secret sharing: inverse
- Compute:
- Secure Multiparty Computation
- Online participation for each request
- Not efficient
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Distributed IBC
- Use SS inverse
- Distributed trust
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Distributed Nguyen’s Acc
- Trusted setup
- Distributed trust
○ SS Direct: Week dynamic ○ SS Inverse: Fully dynamic
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Distributed Accumulator
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None SS Direct SS Inverse Witness generation Accumulate: No check witness: Add member Remove member
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Idea
- Hierarchical Accumulator
○ Improve efficiency in non-trusted model
- Hierarchical SLRS
○ Different privacy levels ○ Set management
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Voting
- Different levels: City, Canton, Country
- Autonomous sets
- Unique identity link across levels
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PoP Party
- Merging parties
- Removing parties
- Attribute based parties
- Multiple attributes for a party
- Distinct parties? Same IBC authority?
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Challenges
- Efficiency
- Efficiency
- Efficiency
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Summary
- Accumulator
- Linkable Ring Signature
- Identity Based Cryptography
- Distributed Authority
- Distributed Identity Based Short Linkable Ring
Signature (DIBSLRS)
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RSA
- Accumulator
- Short Linkable Ring Signature (SLRS)
- Authority
- Certificate public key
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