Kim, Myungsun; Kim, Jihye; Cheon, Jung Hee Compress multiple ciphertexts using ElGamal encryption schemes. (English) Zbl 1296.94125 J. Korean Math. Soc. 50, No. 2, 361-377 (2013). Summary: In this work we deal with the problem of how to squeeze multiple ciphertexts without losing original message information. To do so, we formalize the notion of decomposability for public-key encryption and investigate why adding decomposability is challenging. We construct an ElGamal encryption scheme over extension fields, and show that it supports the efficient decomposition. We then analyze security of our scheme under the standard DDH assumption, and evaluate the performance of our construction. MSC: 94A60 Cryptography 11T71 Algebraic coding theory; cryptography (number-theoretic aspects) 14G50 Applications to coding theory and cryptography of arithmetic geometry Keywords:ciphertext compression; decomposability; message rate PDF BibTeX XML Cite \textit{M. Kim} et al., J. Korean Math. Soc. 50, No. 2, 361--377 (2013; Zbl 1296.94125) Full Text: DOI