IEICE TRANSACTIONS on Fundamentals
A Setup-Free Threshold Encryption Scheme for the Bitcoin Protocol and Its Applications
Summary :
Let us consider a situation where someone wants to encrypt his/her will on an existing blockchain, e.g. Bitcoin, and allow an encrypted will to be decryptable only if designated members work together. At a first glance, such a property seems to be easily provided by using conventional threshold encryption. However, this idea cannot be straightforwardly implemented since key pairs for an encryption mechanism is additionally required. In this paper, we propose a new threshold encryption scheme in which key pairs for ECDSA that are already used in the Bitcoin protocol can be directly used as they are. Namely, a unique key pair can be simultaneously used for both ECDSA and our threshold encryption scheme without losing security. Furthermore, we implemented our scheme on the Bitcoin regtest network, and show that it is fairly practical. For example, the execution time of the encryption algorithm Enc (resp., the threshold decryption algorithm Dec) is 0.2sec. (resp., 0.3sec.), and the total time is just only 3sec. including all the cryptographic processes and network communications for a typical parameter setting. Also, we discuss several applications of our threshold encryption scheme in detail: Claiming priority of intellectual property, sealed-bid auction, lottery, and coin tossing service.
- Publication
- IEICE TRANSACTIONS on Fundamentals Vol.E103-A No.1 pp.150-164
- Publication Date
- 2020/01/01
- Publicized
- Online ISSN
- 1745-1337
- DOI
- 10.1587/transfun.2019CIP0018
- Type of Manuscript
- Special Section PAPER (Special Section on Cryptography and Information Security)
- Category
Authors
Goichiro HANAOKA
National Institute of Advanced Industrial Science and Technology (AIST)
Yusuke SAKAI
National Institute of Advanced Industrial Science and Technology (AIST)
Toshiya SHIMIZU
FUJITSU Laboratories Ltd.
Takeshi SHIMOYAMA
FUJITSU Laboratories Ltd.
SeongHan SHIN
National Institute of Advanced Industrial Science and Technology (AIST)
Keyword
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Goichiro HANAOKA, Yusuke SAKAI, Toshiya SHIMIZU, Takeshi SHIMOYAMA, SeongHan SHIN, "A Setup-Free Threshold Encryption Scheme for the Bitcoin Protocol and Its Applications" in IEICE TRANSACTIONS on Fundamentals,
vol. E103-A, no. 1, pp. 150-164, January 2020, doi: 10.1587/transfun.2019CIP0018.
Abstract: Let us consider a situation where someone wants to encrypt his/her will on an existing blockchain, e.g. Bitcoin, and allow an encrypted will to be decryptable only if designated members work together. At a first glance, such a property seems to be easily provided by using conventional threshold encryption. However, this idea cannot be straightforwardly implemented since key pairs for an encryption mechanism is additionally required. In this paper, we propose a new threshold encryption scheme in which key pairs for ECDSA that are already used in the Bitcoin protocol can be directly used as they are. Namely, a unique key pair can be simultaneously used for both ECDSA and our threshold encryption scheme without losing security. Furthermore, we implemented our scheme on the Bitcoin regtest network, and show that it is fairly practical. For example, the execution time of the encryption algorithm Enc (resp., the threshold decryption algorithm Dec) is 0.2sec. (resp., 0.3sec.), and the total time is just only 3sec. including all the cryptographic processes and network communications for a typical parameter setting. Also, we discuss several applications of our threshold encryption scheme in detail: Claiming priority of intellectual property, sealed-bid auction, lottery, and coin tossing service.
URL: https://global.ieice.org/en_transactions/fundamentals/10.1587/transfun.2019CIP0018/_p
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@ARTICLE{e103-a_1_150,
author={Goichiro HANAOKA, Yusuke SAKAI, Toshiya SHIMIZU, Takeshi SHIMOYAMA, SeongHan SHIN, },
journal={IEICE TRANSACTIONS on Fundamentals},
title={A Setup-Free Threshold Encryption Scheme for the Bitcoin Protocol and Its Applications},
year={2020},
volume={E103-A},
number={1},
pages={150-164},
abstract={Let us consider a situation where someone wants to encrypt his/her will on an existing blockchain, e.g. Bitcoin, and allow an encrypted will to be decryptable only if designated members work together. At a first glance, such a property seems to be easily provided by using conventional threshold encryption. However, this idea cannot be straightforwardly implemented since key pairs for an encryption mechanism is additionally required. In this paper, we propose a new threshold encryption scheme in which key pairs for ECDSA that are already used in the Bitcoin protocol can be directly used as they are. Namely, a unique key pair can be simultaneously used for both ECDSA and our threshold encryption scheme without losing security. Furthermore, we implemented our scheme on the Bitcoin regtest network, and show that it is fairly practical. For example, the execution time of the encryption algorithm Enc (resp., the threshold decryption algorithm Dec) is 0.2sec. (resp., 0.3sec.), and the total time is just only 3sec. including all the cryptographic processes and network communications for a typical parameter setting. Also, we discuss several applications of our threshold encryption scheme in detail: Claiming priority of intellectual property, sealed-bid auction, lottery, and coin tossing service.},
keywords={},
doi={10.1587/transfun.2019CIP0018},
ISSN={1745-1337},
month={January},}
Copy
TY - JOUR
TI - A Setup-Free Threshold Encryption Scheme for the Bitcoin Protocol and Its Applications
T2 - IEICE TRANSACTIONS on Fundamentals
SP - 150
EP - 164
AU - Goichiro HANAOKA
AU - Yusuke SAKAI
AU - Toshiya SHIMIZU
AU - Takeshi SHIMOYAMA
AU - SeongHan SHIN
PY - 2020
DO - 10.1587/transfun.2019CIP0018
JO - IEICE TRANSACTIONS on Fundamentals
SN - 1745-1337
VL - E103-A
IS - 1
JA - IEICE TRANSACTIONS on Fundamentals
Y1 - January 2020
AB - Let us consider a situation where someone wants to encrypt his/her will on an existing blockchain, e.g. Bitcoin, and allow an encrypted will to be decryptable only if designated members work together. At a first glance, such a property seems to be easily provided by using conventional threshold encryption. However, this idea cannot be straightforwardly implemented since key pairs for an encryption mechanism is additionally required. In this paper, we propose a new threshold encryption scheme in which key pairs for ECDSA that are already used in the Bitcoin protocol can be directly used as they are. Namely, a unique key pair can be simultaneously used for both ECDSA and our threshold encryption scheme without losing security. Furthermore, we implemented our scheme on the Bitcoin regtest network, and show that it is fairly practical. For example, the execution time of the encryption algorithm Enc (resp., the threshold decryption algorithm Dec) is 0.2sec. (resp., 0.3sec.), and the total time is just only 3sec. including all the cryptographic processes and network communications for a typical parameter setting. Also, we discuss several applications of our threshold encryption scheme in detail: Claiming priority of intellectual property, sealed-bid auction, lottery, and coin tossing service.
ER -
English
