1. Review of Certificateless Cryptography Yu-Chi Chen

2. Outline. Introduction Review of CL-PKC 2016/5/31 2

3. Introduction. (3/4) ID-PKC (Shamir, 1984; Boneh and Franklin, 2003) – The public key is the user’s identity without a certificate. – more efficient than conventional PKI (need CA). CL-PKC(Al-Riyami and Paterson, 2003) – It solves the key escrow problem of ID-PKC. 2016/5/31 3

4. Introduction. (4/4) Identity-based encryption with keyword search (Abdalla et al., 2008 from J. Crypto.) – Generic construction & security model 2016/5/31 4

5. Outline. Introduction Review of CL-PKC 2016/5/31 5

6. Review of CL-PKC 2016/5/31 6 KGC user: ID Set the user’s partial-private-key msk, mpk ppk via SC Set the user’s public/private key pair (pk ID, sk ID ) where sk ID =(ppk, sv ID ) public-board

7. Review of CL-PKC 2016/5/31 7 KGC user: ID Set the user’s partial-private-key msk, mpk ppk via SC Set the user’s public/private key pair (pk ID, sk ID ) where sk ID =(ppk, sv ID ) public-board pk ID Achieve level-3 security

8. Review of CL-PKC Type 1 adversary cannot access the master-key, but can replace anyone’s public key. Type 2 adversary can access the master-key, but cannot replace anyone’s public key. 2016/5/31 8