Encryption to the Future A Paradigm for Sending Secret Messages to Future (Anonymous) Committees
【Author】 Campanelli, Matteo; David, Bernardo; Khoshakhlagh, Hamidreza; Konring, Anders; Nielsen, Jesper Buus
【Source】ADVANCES IN CRYPTOLOGY-ASIACRYPT 2022, PT III
【影响因子】
【Abstract】A number of recent works have constructed cryptographic protocols with flavors of adaptive security by having a randomly-chosen anonymous committee run at each round. Since most of these protocols are stateful, transferring secret states from past committees to future, but still unknown, committees is a crucial challenge. Previous works have tackled this problem with approaches tailor-made for their specific setting, which mostly rely on using a blockchain to orchestrate auxiliary committees that aid in the state hand-over process. In this work, we look at this challenge as an important problem on its own and initiate the study of Encryption to the Future (EtF) as a cryptographic primitive. First, we define a notion of an EtF scheme where time is determined with respect to an underlying blockchain and a lottery selects parties to receive a secret message at some point in the future. While this notion seems overly restrictive, we establish two important facts: 1. if used to encrypt towards parties selected in the "far future", EtF implies witness encryption for NP over a blockchain; 2. if used to encrypt only towards parties selected in the "near future", EtF is not only sufficient for transferring state among committees as required by previous works, but also captures previous tailor-made solutions. To corroborate these results, we provide a novel construction of EtF based on witness encryption over commitments (cWE), which we instantiate from a number of standard assumptions via a construction based on generic cryptographic primitives. Finally, we show how to use "near future" EtF to obtain "far future" EtF with a protocol based on an auxiliary committee whose communication complexity is independent of the length of plaintext messages being sent to the future. [Campanelli, Matteo] Protocol Labs, San Francisco, CA 94102 USA; [Campanelli, Matteo; Khoshakhlagh, Hamidreza; Nielsen, Jesper Buus] Aarhus Univ, Aarhus, Denmark; [David, Bernardo; Konring, Anders] IT Univ Copenhagen, Copenhagen, Denmark Aarhus University; IT University Copenhagen Campanelli, M (通讯作者)，Protocol Labs, San Francisco, CA 94102 USA. matteo@protocol.ai; beda@itu.dk; hamidreza@cs.au.dk; konr@itu.dk; jbn@cs.au.dk Concordium Foundation; Independent Research Fund Denmark (IRFD) [9040-00399B, 9131-00075B, 0165-00079B]; Concordium Foundation under Concordium Blockchain Research Center, Aarhus; IRFD [9040-00399B]; Danish Independent Research Council [DFF-8021-00366B]; Carlsberg Foundation under the Semper Ardens Research Project [CF18-112] Concordium Foundation; Independent Research Fund Denmark (IRFD); Concordium Foundation under Concordium Blockchain Research Center, Aarhus; IRFD; Danish Independent Research Council(Det Frie Forskningsrad (DFF)); Carlsberg Foundation under the Semper Ardens Research Project Bernardo David is supported by the Concordium Foundation and by the Independent Research Fund Denmark (IRFD) grants number 9040-00399B (TrA2C), 9131-00075B (PUMA) and 0165-00079B. Hamidreza Khoshakhlagh has been funded by the Concordium Foundation under Concordium Blockchain Research Center, Aarhus. Anders Konring is supported by the IRFD grant number 9040-00399B (TrA2C). Jesper Buus Nielsen is partially funded by the Concordium Foundation; The Danish Independent Research Council under Grant-ID DFF-8021-00366B (BETHE); The Carlsberg Foundation under the Semper Ardens Research Project CF18-112 (BCM). 23 0 0 0 0 SPRINGER INTERNATIONAL PUBLISHING AG CHAM GEWERBESTRASSE 11, CHAM, CH-6330, SWITZERLAND 0302-9743 1611-3349 978-3-031-22968-8; 978-3-031-22969-5 LECT NOTES COMPUT SC 2022 13793 151 180 10.1007/978-3-031-22969-5_6 http://dx.doi.org/10.1007/978-3-031-22969-5_6 30 Computer Science, Information Systems; Computer Science, Theory & Methods; Mathematics, Applied Conference Proceedings Citation Index - Science (CPCI-S) Computer Science; Mathematics BU9WU Green Submitted 2023-05-06 WOS:000964580500006
【Keywords】
【发表时间】2022
【收录时间】2023-05-14
【文献类型】理论模型
【主题类别】
区块链技术-核心技术-加密算法
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