Abstract
Currently, Gasper, the implemented consensus protocol of Ethereum, takes between 64 and 95 slots to finalize blocks. Because of that, a significant portion of the chain is susceptible to reorgs. The possibility to capture MEV (Maximum Extractable Value) through such reorgs can then disincentivize honestly following the protocol, breaking the desired correspondence of honest and rational behavior. Moreover, the relatively long time to finality forces users to choose between economic security and faster transaction confirmation. This motivates the study of the so-called single slot finality protocols: consensus protocols that finalize a block in each slot and, more importantly, that finalize the block proposed at a given slot within such slot.
In this work we propose a simple, non-blackbox protocol that combines a synchronous dynamically available protocol with a partially synchronous finality gadget, resulting in a consensus protocol that can finalize one block per slot, paving the way to single slot finality within Ethereum. Importantly, the protocol we present can finalize the block proposed in a slot, within such slot.
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Notes
- 1.
If the protocol satisfies liveness, then at least one honest proposal is added to the confirmed chain of all active validators every \(T_\textsf{conf}\) slots. Since honest validators include all transactions they see, this ensures that transactions are confirmed within time \(T_\textsf{conf}+ \varDelta \) (assuming infinite block sizes or manageable transaction volume).
- 2.
D’Amato and Zanolini [7] implement RLMD-GHOST with fast confirmation with \(k=3\varDelta \) (Appendix B [7]). However, we will consider \(k=4\varDelta \), following the approach taken by D’Amato et al. [6] when presenting Goldfish with fast confirmation. We will show how RLMD-GHOST with fast confirmation can be changed into its variant with \(k=4\varDelta \) in Sect. 4 while presenting our protocol.
- 3.
Observe that D’Amato et al. [6] actually refer to awake validators to indicate what we call active, and to dreamy validators to indicate what we call awake (but not active).
- 4.
For simplicity, we omit a reference to the parent block.
- 5.
With some minor changes, as RLMD-GHOST still has \(3\varDelta \) rounds per slots, by requiring an optimistic assumption on network latency in order for fast confirmations to be live.
- 6.
References
Asgaonkar, A.: Remove equivocating validators from fork choice consideration. https://github.com/ethereum/consensus-specs/pull/2845
Buterin, V.: Paths toward single-slot finality (2023). https://notes.ethereum.org/@vbuterin/single_slot_finality
Buterin, V., Griffith, V.: Casper the friendly finality gadget. CoRR abs/1710.09437 (2017). http://arxiv.org/abs/1710.09437
Buterin, V., et al.: Combining GHOST and Casper (2020)
Castro, M., Liskov, B.: Practical byzantine fault tolerance. In: Seltzer, M.I., Leach, P.J. (eds.) Proceedings of the Third USENIX Symposium on Operating Systems Design and Implementation (OSDI), New Orleans, Louisiana, USA, February 22–25, 1999, pp. 173–186. USENIX Association (1999)
D’Amato, F., Neu, J., Tas, E.N., Tse, D.: No more attacks on proof-of-stake ethereum? CoRR abs/2209.03255 (2022). https://doi.org/10.48550/arXiv.2209.03255
D’Amato, F., Zanolini, L.: Recent latest message driven ghost: Balancing dynamic availability with asynchrony resilience (2023). https://arxiv.org/abs/2302.11326
Dwork, C., Lynch, N.A., Stockmeyer, L.J.: Consensus in the presence of partial synchrony. J. ACM 35(2), 288–323 (1988)
Gilbert, S., Lynch, N.A.: Brewer’s conjecture and the feasibility of consistent, available, partition-tolerant web services. SIGACT News 33(2), 51–59 (2002)
Kane, D., Fackler, A., Gagol, A., Straszak, D.: Highway: efficient consensus with flexible finality. CoRR abs/2101.02159 (2021). https://arxiv.org/abs/2101.02159
Lewis-Pye, A., Roughgarden, T.: Resource pools and the CAP theorem. CoRR abs/2006.10698 (2020). https://arxiv.org/abs/2006.10698
Malkhi, D., Momose, A., Ren, L.: Byzantine consensus under fully fluctuating participation. IACR Cryptol. ePrint Arch, p. 1448 (2022)
Momose, A., Ren, L.: Constant latency in sleepy consensus. In: Yin, H., Stavrou, A., Cremers, C., Shi, E. (eds.) Proceedings of the 2022 ACM SIGSAC Conference on Computer and Communications Security, CCS 2022, Los Angeles, CA, USA, November 7–11, 2022, pp. 2295–2308. ACM (2022)
Neu, J., Tas, E.N., Tse, D.: Ebb-and-flow protocols: a resolution of the availability-finality dilemma. In: 42nd IEEE Symposium on Security and Privacy, SP 2021, San Francisco, CA, USA, 24–27 May 2021, pp. 446–465. IEEE (2021)
Pass, R., Shi, E.: The sleepy model of consensus. In: Takagi, T., Peyrin, T. (eds.) Advances in Cryptology – ASIACRYPT 2017: 23rd International Conference on the Theory and Applications of Cryptology and Information Security, Hong Kong, China, December 3-7, 2017, Proceedings, Part II, pp. 380–409. Springer International Publishing, Cham (2017). https://doi.org/10.1007/978-3-319-70697-9_14
Sompolinsky, Y., Zohar, A.: Secure high-rate transaction processing in bitcoin. In: Böhme, R., Okamoto, T. (eds.) Financial Cryptography and Data Security: 19th International Conference, FC 2015, San Juan, Puerto Rico, January 26-30, 2015, Revised Selected Papers, pp. 507–527. Springer Berlin Heidelberg, Berlin, Heidelberg (2015). https://doi.org/10.1007/978-3-662-47854-7_32
Zamfir, V.: Casper the friendly ghost. a correct-by-construction blockchain consensus protocol. https://github.com/ethereum/research/blob/master/papers/cbc-consensus/AbstractCBC.pdf
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D’Amato, F., Zanolini, L. (2024). A Simple Single Slot Finality Protocol for Ethereum. In: Katsikas, S., et al. Computer Security. ESORICS 2023 International Workshops. ESORICS 2023. Lecture Notes in Computer Science, vol 14398. Springer, Cham. https://doi.org/10.1007/978-3-031-54204-6_23
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