Cryptanalysis of a Hierarchical Identity-Based Encryption Scheme
Hierarchical Identity-Based Encryption (HIBE) is a generalization of identity-based encryption that mirrors an organizational hierarchy, and allows the root Private Key Generator (PKG) to distribute the workload of key generations to lower-level PKGs In Indocrypt'08. ken and Go proposed a new HI BE scheme, and claimed that their scheme is fully chosen-ciphertext secure in the standard model However, by giving a concrete attack, we show that Ren-Gu's HI BE is even not chosen-plaintext secure
hierarchial identity-based encryption chosen-ciphertext attack chosen-plaintext attack