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2020 | OriginalPaper | Chapter

Updatable Blockchains

Authors : Michele Ciampi, Nikos Karayannidis, Aggelos Kiayias, Dionysis Zindros

Published in: Computer Security – ESORICS 2020

Publisher: Springer International Publishing

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Abstract

Software updates for blockchain systems become a real challenge when they impact the underlying consensus mechanism. The activation of such changes might jeopardize the integrity of the blockchain by resulting in chain splits. Moreover, the software update process should be handed over to the community and this means that the blockchain should support updates without relying on a trusted party. In this paper, we introduce the notion of updatable blockchains and show how to construct blockchains that satisfy this definition. Informally, an updatable blockchain is a secure blockchain and in addition it allows to update its protocol preserving the history of the chain. In this work, we focus only on the processes that allow securely switching from one blockchain protocol to another assuming that the blockchain protocols are correct. That is, we do not aim at providing a mechanism that allows reaching consensus on what is the code of the new blockchain protocol. We just assume that such a mechanism exists (like the one proposed in NDSS 2019 by Zhang et al.), and show how to securely go from the old protocol to the new one. The contribution of this paper can be summarized as follows. We provide the first formal definition of updatable ledgers and propose the description of two compilers. These compilers take a blockchain and turn it into an updatable blockchain. The first compiler requires the structure of the current and the updated blockchain to be very similar (only the structure of the blocks can be different) but it allows for an update process more simple, efficient. The second compiler that we propose is very generic (i.e., makes few assumptions on the similarities between the structure of the current blockchain and the update blockchain). The drawback of this compiler is that it requires the new blockchain to be resilient against a specific adversarial behaviour and requires all the honest parties to be online during the update process. However, we show how to get rid of the latest requirement (the honest parties being online during the update) in the case of proof-of-work and proof-of-stake ledgers.

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previous chapter How to Model the Bribery Attack: A Practical Quantification Method in Blockchain

next chapter PrivacyGuard: Enforcing Private Data Usage Control with Blockchain and Attested Off-Chain Contract Execution

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With slight abuse of terminology we use the words ledger and blockchain interchangeably.

As a global setup, \(\mathcal {G}_{\mathtt {clock}}\) also exists in the ideal world and the ledger connects to it to keep track of rounds.

A rushing adversary waits to receive the messages from all the honest parties and then computes its reply. Note that this means that, in general, the adversary is always able to see the output of the computation before the honest parties do.

We also show that we can relax the requirement on the honest parties being online during the update for the case of PoW ledgers.

Zcash. https://z.cash/

Avarikioti, G., Käppeli, L., Wang, Y., Wattenhofer, R.: Bitcoin security under temporary dishonest majority. In: Goldberg, I., Moore, T. (eds.) FC 2019. LNCS, vol. 11598, pp. 466–483. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-32101-7_28CrossRef

Badertscher, C., Gazi, P., Kiayias, A., Russell, A., Zikas, V.: Ouroboros genesis: composable proof-of-stake blockchains with dynamic availability. In: Lie, D., Mannan, M., Backes, M., Wang, X. (eds.) ACM CCS 2018, pp. 913–930. ACM Press, October 2018. https://doi.org/10.1145/3243734.3243848

Badertscher, C., Maurer, U., Tschudi, D., Zikas, V.: Bitcoin as a transaction ledger: a composable treatment. In: Katz, J., Shacham, H. (eds.) CRYPTO 2017. LNCS, vol. 10401, pp. 324–356. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-63688-7_11CrossRef

Canetti, R.: Universally composable security: a new paradigm for cryptographic protocols. In: 42nd FOCS, pp. 136–145. IEEE Computer Society Press, October 2001. https://doi.org/10.1109/SFCS.2001.959888

Canetti, R., Dodis, Y., Pass, R., Walfish, S.: Universally composable security with global setup. In: Vadhan, S.P. (ed.) TCC 2007. LNCS, vol. 4392, pp. 61–85. Springer, Heidelberg (2007). https://doi.org/10.1007/978-3-540-70936-7_4CrossRef

Coretti, S., Garay, J., Hirt, M., Zikas, V.: Constant-round asynchronous multi-party computation based on one-way functions. In: Cheon, J.H., Takagi, T. (eds.) ASIACRYPT 2016. LNCS, vol. 10032, pp. 998–1021. Springer, Heidelberg (2016). https://doi.org/10.1007/978-3-662-53890-6_33CrossRef

Decred: Decred white paper (2019). https://docs.decred.org/

Duffield, E., Diaz, D.: Dash: a payments-focused cryptocurrency (2018). https://github.com/dashpay/dash/wiki/Whitepaper

10.

Garay, J., Kiayias, A.: SoK: a consensus taxonomy in the blockchain era. In: Jarecki, S. (ed.) CT-RSA 2020. LNCS, vol. 12006, pp. 284–318. Springer, Cham (2020). https://doi.org/10.1007/978-3-030-40186-3_13CrossRefMATH

11.

Garay, J., Kiayias, A., Leonardos, N.: The bitcoin backbone protocol: analysis and applications. In: Oswald, E., Fischlin, M. (eds.) EUROCRYPT 2015. LNCS, vol. 9057, pp. 281–310. Springer, Heidelberg (2015). https://doi.org/10.1007/978-3-662-46803-6_10CrossRef

12.

Garay, J.A., Kiayias, A., Leonardos, N., Panagiotakos, G.: Bootstrapping the blockchain, with applications to consensus and fast PKI setup. In: Abdalla, M., Dahab, R. (eds.) PKC 2018. LNCS, vol. 10770, pp. 465–495. Springer, Cham (2018). https://doi.org/10.1007/978-3-319-76581-5_16CrossRef

13.

Gazi, P., Kiayias, A., Zindros, D.: Proof-of-stake sidechains. In: 2019 IEEE Symposium on Security and Privacy, pp. 139–156. IEEE Computer Society Press, May 2019. https://doi.org/10.1109/SP.2019.00040

14.

Goodman, L.: Tezos—a self-amending crypto-ledger white paper (2014). https://tezos.com/static/white_paper-2dc8c02267a8fb86bd67a108199441bf.pdf

15.

Katz, J., Maurer, U., Tackmann, B., Zikas, V.: Universally composable synchronous computation. In: Sahai, A. (ed.) TCC 2013. LNCS, vol. 7785, pp. 477–498. Springer, Heidelberg (2013). https://doi.org/10.1007/978-3-642-36594-2_27CrossRef

16.

Zhang, B., Oliynykov, R., Balogun, H.: A treasury system for cryptocurrencies: enabling better collaborative intelligence. In: NDSS 2019. The Internet Society, February 2019

Title: Updatable Blockchains
Authors: Michele Ciampi
Nikos Karayannidis
Aggelos Kiayias
Dionysis Zindros
Publisher: Springer International Publishing
Book: Computer Security – ESORICS 2020
Print ISBN: 978-3-030-59012-3

Electronic ISBN: 978-3-030-59013-0

Copyright Year: 2020
DOI: https://doi.org/10.1007/978-3-030-59013-0_29

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