Common Contracts

Agreement Protocols

June 30th, 2006

• Filed
  June 30th, 2006

Certificateless public key cryptography (CL-PKC) was proposed to overcome the weak- nesses of the public key infrastructure (PKI) and identity-based cryptography (ID-PKC). In PKI, certificates are used to provide the authenticity of public keys. However, a PKI faces many challenges in practice, such as the scalability of the infrastructure and certifi- cate management (distribution, revocation, storage, and validation costs). ID-PKC does not use certificates, but employs a key generation center (KGC) that will know every user’s private key. Hence, the KGC will also be able to trace each user transaction and may cause loss of privacy if it’s not trusted. In CL-PKC, on the other hand, the KGC does not have this information. Thus, CL-PKC is often considered a cross between PKI and ID-PKC.‌‌