Professor Eiichiro Fujisaki, Security and Networks Area, has received Public Key Cryptography Conference 2019 Test of Time Award.

The International Conference on Practice and Theory in Public Key Cryptography (PKC) is one of the main annual conferences sponsored by the International Association for Cryptologic Research (IACR). PKC has been focusing on all aspects of public-key cryptography, attracting cutting-edge results from world-renowned scientists in the area.

The PKC Test of Time Award recognizes outstanding papers, published in PKC about 15 years ago, making a significant contribution to the theory and practice of public key cryptography, preferably with influence either on foundations or on the practice of the field. The inaugural PKC Test of Time Award was given in PKC 2019 for papers published in the conference's initial years of early 2000s and late 1990s. In the first few years a number of papers from a few different initial years of PKC can be recognized, and later on the award will typically recognize one year at a time with one or two papers.

[References]
* International Association for Cryptologic Research (IACR)
* PKC Test of Time Award (Information)
* PKC 2019 　

■Date Awarded
April 16, 2019

■Title
How to Enhance the Security of Public-Key Encryption at Minimum Cost

■Authors
Eiichiro Fujisaki and Tatsuaki Okamoto

■Abstract
This paper presents a simple and generic conversion from a public-key encryption scheme that is indistinguishable against chosen-plaintext attacks into a public-key encryption scheme that is indistinguishable against adaptive chosen-ciphertext attacks in the random oracle model. The scheme obtained by the conversion is as efficient as the original encryption scheme and the security reduction is very tight in the exact security manner.

■Comment from PKC 2019 Test of Time Award Committee
This paper proposes a very powerful and useful trick of transforming IND-CPA encryption scheme to IND-CCA encryption scheme in the Random Oracle model. This trick, together with succeeding Crypto results with the same authors, is called Fujisaki-Okamoto transformation and widely used to enhance security of many other crypto primitives.

■Comment from Professor Fujisaki
I am greatly honored to receive this award. The paper proposes a transformation of a weak encryption scheme to a strong one. Quite fortunately, our proposal, together with our successive one published at CRYPTO, has been widely used and extensively referred to in the literature since then. I couldn't imagine it at all when I took a presentation at PKC 1999. I am really happy if I contributed to the progress of cryptographic research even just a little.

April 26, 2019