## Cryptology ePrint Archive: Report 2007/210

Efficient chosen ciphertext secure PKE scheme with short ciphertext

Xianhui Lu, Xuejia Lai, Dake He, Guomin Li

Abstract: Kurosawa and Matsuo\cite{Kurosawa20042} showed that MAC can be removed from DHIES while the underlying symmetric-key encryption(SKE) scheme is secure against adaptive chosen ciphertext attacks(IND-CCA). We construct a variant of DHIES which eliminate the MAC while the SKE scheme is secure against passive attacks(IND-PA). Since IND-PA is the basic requirement of SKE schemes, the new scheme is more flexible than \cite{Kurosawa20042}. Our new scheme can be seen as a combination of a tag-KEM \cite{Abe2005} and a DEM. Our construction offers the first tag-KEM with single element. When the hash function $H$ in the ODH assumption is a non-malleable hash function we can prove that the new scheme is IND-CCA secure under the ODH assumption.

Category / Keywords: PKE, DHIES, tag-KEM, IND-PA

Date: received 2 Jun 2007, last revised 17 Dec 2007, withdrawn 23 Oct 2009

Contact author: luxianhui at gmail com

Available format(s): (-- withdrawn --)

Note: the secure reduction of the scheme is simplified, the title is renamed

Short URL: ia.cr/2007/210

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