Abstract
In this paper we propose a system in which a set of people is able to confidentially communicate using a common session key. Due to required governmental surveillance properties, this key will be escrowed using a multi-party version of the ElGamal cryptosystem. The resulting shares of the ciphertext are stored over a set of trusted servers to provide availability and to hamper ciphertext-based attacks. Using a particular tree-based multi-party decryption, the session key can be reconstructed by a tree-structured set of escrow agencies without reconstructing the private ElGamal key and the ciphertext.
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Schaffer, M., Schartner, P. (2005). Key Escrow with Tree-Based Access Structure. In: Gorodetsky, V., Kotenko, I., Skormin, V. (eds) Computer Network Security. MMM-ACNS 2005. Lecture Notes in Computer Science, vol 3685. Springer, Berlin, Heidelberg. https://doi.org/10.1007/11560326_39
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DOI: https://doi.org/10.1007/11560326_39
Publisher Name: Springer, Berlin, Heidelberg
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