Who Am I? Secure Identity Registration on Distributed Ledgers Sarah Azouvi Mustafa Al-Bassam Sarah Meiklejohn (University College London) 1
Cryptocurrencies 2
Cryptocurrencies Pseudonyms 2
Cryptocurrencies Pseudonyms tx(pk A pk B ) 2
Blockchain for distributing benefits? 3
Blockchain for distributing benefits? 3
Blockchain for distributing benefits? 3
Related
Related PKI
Related PKI Anonymous Credentials
Related PKI Anonymous Credentials Identity management on Blockchains
Related PKI Anonymous Credentials Identity management on Blockchains
Related PKI Anonymous Credentials Identity management on Blockchains
Related PKI Anonymous Credentials Identity management on Blockchains
Related PKI Anonymous Credentials Identity management on Blockchains uPort
Related PKI Anonymous Credentials Identity management on Blockchains uPort ChainAnchor
Related PKI Anonymous Credentials Identity management on Blockchains uPort ChainAnchor MIT Digital certificates
Security Registration I’m Alice pk Verification pk 5
Security Registration I’m Alice pk Verification pk 6 6
Security Registration I’m Alice pk Verification pk 6 6
Security Passive verification I’m Alice pk pk 7 7 7
Security Active verification I’m Alice pk pk 8 8 8
Security Attribute integrity I’m Alice pk pk 9 9 9
Security Attribute integrity I’m Alice pk pk 9 9 9
Security Attribute integrity I’m Alice pk pk pk 9 9 9
Security Attribute integrity I’m Alice pk pk pk 9 9 9
Security Attribute privacy I’m Alice ? pk 10
Our constructions 11
Web of trust Registration I’m Alice, my public key is pk tx{pk R (pk,pk rev )} 12
Web of trust Registration I’m Alice, my public key is pk tx{(pk R1, …,pk Rn ) (pk,pk rev1 ,…,pk revn )} 13 13
Web of trust Registration I’m Alice, my public key is pk tx{(pk R1, …,pk Rn ) (pk,pk rev1 ,…,pk revn )} Verification tx? pk rev ? 13 13
Web of trust • Verification: passive (on the blockchain) • Attribute integrity: partially. Registrars cannot impersonate Alice. But malicious coalition of users can collude • Privacy: no Alice + pk 14
Web of trust • Verification: passive (on the blockchain) • Attribute integrity: partially. Registrars cannot impersonate Alice. But malicious coalition of users can collude • Privacy: no Alice + pk 14
Blinded web of trust • Verification: active • Attribute Integrity: partially • Privacy: yes 15
Casascius sk 1 , pk 1 sk 2 pk 1 sk 2 pk 2 =pk 1sk2 pk 2 =pk 1sk2 =g sk1.sk2 16
Multi-Casascius 17 17 17
Multi-Casascius 18 18
Multi-Casascius • Verification: Passive • Attribute Integrity: Satisfied. First registrar verifies id. No registrar knows the private key. • Privacy: yes. As long as one registrar honest 19
Implementation https://github.com/musalbas/trustery 20
Implementation • Add attribute (di ff erent types) • Sign attribute • Add/Sign Blind attribute 21
Implementation 22
Conclusion • Di ff erent methods for achieving registration in public distributed ledgers • Light-weight crypto primitives • Open problem: key recovery 23
Questions? 24
Recommend
More recommend
