2 research outputs found
Multiple and Unlinkable Public Key Encryption without Certificates
We newly propose a multiple and unlinkable identity-based public key
encryption scheme. Unlike the traditional public key encryption and
identity-based encryption schemes, our scheme allows the use of a
various number of identity-based public keys in different groups or
applications while keeping a single decryption key so that the
decryption key can decrypt every ciphertexts encrypted with those
public keys. Also our scheme removes the use of certificates as well
as the key escrow problem so it is functional and practical. Since
our public keys are unlinkable, the user\u27s privacy can be protected
from attackers who collect and trace the user information and
behavior using the known public keys. Furthermore, we suggest a
decryption key renewal protocol to strengthen the security of the
single decryption key. Finally, we prove the security of our scheme
against the adaptive chosen-ciphertext attack under the random
oracle model