Hee Jean Kim

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Broadcast encryption allows a sender to securely distribute messages to a dynamically changing set of users over an insecure channel. In a public key broadcast encryption (PKBE) scheme, this encryption is performed in the public key setting, where the public key is stored in a user's device, or directly transmitted to the receivers along with ciphertexts.(More)
New broadcasting services such as 3DTV and UHDTV are turning up and catching the public attention, because people nowadays like to have more realistic watching experience in TV. However, terrestrial broadcasters have difficulties in launching them, because new terrestrial broadcasting services necessarily need new frequency allocation. As frequency is(More)
In this paper, we show that Chikazawa-Inoue ID-based key system is insecure by collusion, where Chikazawa-Inoue ID-based key system means the key parameters established during the initiation phase. We describe an algorithm factorizing a public key of Trust Center. Since our attack is based on only the key system and has no relation with specific key sharing(More)
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