Abstract
With the development of Ethereum 2.0, the proof-of-stake-based blockchain has become more and more popular. Although not commonly deployed in existing blockchains, many PoS or its variants’ consensus protocols have been proposed. As the same in many other cryptographic systems, the trustworthy randomness is crucial in PoS-based blockchains such as the selection of the block proposer. Since Boneh proposed the primitive of verifiable delay functions in 2018, it has received intensive attention and been used for many applications, among which the most interesting one is to make an unpredictable, unbiased and unstoppable randomness as the Ethereum Minimal VDF randomness beacon. In this paper, we analyze it in an algorithmic aspect, concentrating on the RANDAO scheme with verifiable delay functions to generate unbiased and public-verifiable randomness for such PoS-based blockchains. We analyze Pietrzak’s verifiable delay function and give improvements to the Ethereum 2.0 Randomness beacon based on the benchmark results. We further propose some new ideas to prevent quantum attack and ASICs to break the scheme where verifiable delay functions are used.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Randao git repository. https://github.com/randao/randao
Boneh, D., Bonneau, J., Bünz, B., Fisch, B.: Verifiable delay functions. In: Shacham, H., Boldyreva, A. (eds.) CRYPTO 2018. LNCS, vol. 10991, pp. 757–788. Springer, Cham (2018). https://doi.org/10.1007/978-3-319-96884-1_25
Boneh, D., Bünz, B., Fisch, B.: A survey of two verifiable delay functions. IACR Cryptology ePrint Archive 2018, 712 (2018)
Buterin, V.: Vdf and attacks. ethereum research post (2018). https://ethresear.ch/t/verifiable-delay-functions-and-attacks/2365
Buterin, V., Griffith, V.: Casper the friendly finality gadget. arXiv preprint arXiv:1710.09437 (2017)
Cachin, C., Kursawe, K., Shoup, V.: Random oracles in constantinople: practical asynchronous byzantine agreement using cryptography. J. Cryptol. 18(3), 219–246 (2005)
Chen, J., Micali, S.: Algorand. arXiv preprint arXiv:1607.01341 (2016)
Drake, J.: Minimal vdf randomness beacon. ethereum research post (2018). https://ethresear.ch/t/minimal-vdf-randomness-beacon/3566
Ephraim, N., Freitag, C., Komargodski, I., Pass, R.: Continuous verifiable delay functions. Technical Report, IACR Cryptology ePrint Archive, 2019: 619 (2019)
Kiayias, A., Russell, A., David, B., Oliynykov, R.: Ouroboros: a provably secure proof-of-stake blockchain protocol. In: Katz, J., Shacham, H. (eds.) CRYPTO 2017. LNCS, vol. 10401, pp. 357–388. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-63688-7_12
Lenstra, A.K., Wesolowski, B.: Trustworthy public randomness with sloth, unicorn, and trx. Int. J. Appl. Crypt. 3(4), 330–343 (2017)
Long, J., Wei, R.: Nakamoto consensus with verifiable delay puzzle. arXiv preprint arXiv:1908.06394 (2019)
Mansat, P. https://github.com/PaulMansat/Bachelor_Project_VDF_273856. Accessed 19 May 2020
Pietrzak, K.: Simple verifiable delay functions. In: 10th Innovations in Theoretical Computer Science Conference (ITCS 2019). Schloss Dagstuhl-Leibniz-Zentrum fuer Informatik (2018)
Rabin, M.O.: Transaction protection by beacons. J. Comput. Syst. Sci. 27(2), 256–267 (1983)
Rivest, R.L., Shamir, A., Wagner, D.A.: Time-lock puzzles and timed-release crypto (1996)
Wang, G., Shi, Z.J., Nixon, M., Han, S.: Sok: Sharding on blockchain. In: Proceedings of the 1st ACM Conference on Advances in Financial Technologies, pp. 41–61 (2019)
Wesolowski, B.: Efficient verifiable delay functions. In: Ishai, Y., Rijmen, V. (eds.) EUROCRYPT 2019. LNCS, vol. 11478, pp. 379–407. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-17659-4_13
Zheng, Z., Xie, S., Dai, H.N., Chen, X., Wang, H.: Blockchain challenges and opportunities: a survey. Int. J. Web Grid Serv. 14(4), 352–375 (2018)
Acknowledgments
Some parts related to implementation and benchmark utilize the work and report of Paul Mansat during his bachelor project. We thank him for his original coding and helpful discussions on the implementation. We thank the anonymous reviewers for their useful comments and suggestions. The authors were partially supported by the National Key R&D Program of China, 2017YFB0802000 and Natural Science Foundation of China, 61672059.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2020 Springer Nature Singapore Pte Ltd.
About this paper
Cite this paper
Liu, L., Xu, M. (2020). Analysis of the Randomness Generation for PoS-Based Blockchains with Verifiable Delay Functions. In: Zheng, Z., Dai, HN., Fu, X., Chen, B. (eds) Blockchain and Trustworthy Systems. BlockSys 2020. Communications in Computer and Information Science, vol 1267. Springer, Singapore. https://doi.org/10.1007/978-981-15-9213-3_51
Download citation
DOI: https://doi.org/10.1007/978-981-15-9213-3_51
Published:
Publisher Name: Springer, Singapore
Print ISBN: 978-981-15-9212-6
Online ISBN: 978-981-15-9213-3
eBook Packages: Computer ScienceComputer Science (R0)