Patent ID: 7653201

Claim:
A computer implemented method of a trusted entity CA facilitating generation of a public key by a correspondent A in an electronic data communication system using implicit certificates, said method comprising the steps of: a cryptographic unit of said trusted entity CA selecting a unique identity I A distinguishing said correspondent A; said cryptographic unit generating public key reconstruction public data γ A for said correspondent A by mathematically combining a private value of said trusted entity CA and information made public by said trusted entity CA to obtain a pair (I A , γ A ) serving as an implicit certificate for said correspondent A; said cryptographic unit generating a private key α for said correspondent A using said implicit certificate and said private value of said trusted entity CA such that said public key is computable by combining said data γ A and said private key α, wherein generating said private key α comprises generating a value ƒ being a function of said pair (I A , γ A ) including a hash of said pair (I A , γ A ) and evaluating said private key α from an equation comprising ƒ and said private value of said trusted entity CA; and said cryptographic unit providing a signature (I A , α, γ A ) to said correspondent A over a secure channel of said data communication system.