Abstract
“Confidential Transactions”, integrated transactions of commitments, signatures, and zero-knowledge range proofs, are favored for their ability to hide transaction amounts. In the real world, multi-party fund transfers are highly desirable for personal and business security. Unfortunately, existing unproven Multi-Party Confidential Transactions are linear in the (exact) number of co-owners; hence they are not compact, very scalable, nor private (leak number of users and their public information). In this study, we provide provably secure private, compact Multi-Party Confidential Transactions, in both the “unanimous” N-out-of-N and “threshold” T-out-of-N settings. Unlike other schemes, our multi-party transactions have the size of single-owner transactions and hide the number of participants. To the best of our knowledge, ours is the first proven secure multi-party and threshold confidential transaction protocol.
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- 1.
Note that we do not specify how the asset details are recorded in the cash system, meaning that the asset details may be permanent like in Bitcoin blockchain or aggregatable in Mimblewimble variants. The confidential transaction protocol is compatible with any secure cash system, which prevents double spending if the unspent assets are accessible.
- 2.
A wallet is an application that securely stores secret keys. Generally, wallets are password protected.
- 3.
Multiple wallets with different keys replicate the shadow co-owners of the same owner.
- 4.
This property is an additional property that is overlooked by the original Bulletproofs range proofs [6].
References
Barber, S., Boyen, X., Shi, E., Uzun, E.: Bitter to better — how to make bitcoin a better currency. In: Keromytis, A.D. (ed.) Financial Cryptography and Data Security. LNCS, vol. 7397, pp. 399–414. Springer, Heidelberg (2012). https://doi.org/10.1007/978-3-642-32946-3_29
beam.mw: Scalable confidential cryptocurrency mimblewimble implementation. https://www.beam.mw/. Accessed 27 May 2020
Boneh, D., Drijvers, M., Neven, G.: Compact multi-signatures for smaller blockchains. In: Peyrin, T., Galbraith, S. (eds.) ASIACRYPT 2018. LNCS, vol. 11273, pp. 435–464. Springer, Cham (2018). https://doi.org/10.1007/978-3-030-03329-3_15
Boneh, D., Lynn, B., Shacham, H.: Short signatures from the weil pairing. In: Boyd, C. (ed.) ASIACRYPT 2001. LNCS, vol. 2248, pp. 514–532. Springer, Heidelberg (2001). https://doi.org/10.1007/3-540-45682-1_30
Bootle, J., Cerulli, A., Chaidos, P., Groth, J., Petit, C.: Efficient zero-knowledge arguments for arithmetic circuits in the discrete log setting. In: Fischlin, M., Coron, J.-S. (eds.) EUROCRYPT 2016. LNCS, vol. 9666, pp. 327–357. Springer, Heidelberg (2016). https://doi.org/10.1007/978-3-662-49896-5_12
Bünz, B., Bootle, J., Boneh, D., Poelstra, A., Wuille, P., Maxwell, G.: Bulletproofs: efficient range proofs for confidential transactions. In: IEEE SP, May 2018 (2017)
Cryptograph, D.: Crate bulletproofs - module bulletproofs::range proof MPC. https://doc-internal.dalek.rs/bulletproofs/range_proof_mpc/index.html. Accessed 21 Nov 2019
Fuchsbauer, G., Orrù, M., Seurin, Y.: Aggregate cash systems: a cryptographic investigation of mimblewimble. In: Ishai, Y., Rijmen, V. (eds.) EUROCRYPT 2019. LNCS, vol. 11476, pp. 657–689. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-17653-2_22
Horster, P., Michels, M., Petersen, H.: Meta-multisignature schemes based on the discrete logarithm problem. Information Security — the Next Decade. IAICT, pp. 128–142. Springer, Boston, MA (1995). https://doi.org/10.1007/978-0-387-34873-5_11
Jedusor, T.E.: Mimblewimble (2016)
Langford, S.K.: Weaknesses in some threshold cryptosystems. In: Koblitz, N. (ed.) CRYPTO 1996. LNCS, vol. 1109, pp. 74–82. Springer, Heidelberg (1996). https://doi.org/10.1007/3-540-68697-5_6
Maxwell, G.: Confidential transactions (2015). https://people.xiph.org/$~$greg/confidential_values.txt. Accessed 09 May 2016
Maxwell, G., Poelstra, A.: Borromean ring signatures (2015)
Maxwell, G., Poelstra, A., Seurin, Y., Wuille, P.: Simple schnorr multi-signatures with applications to bitcoin, pp. 1–26. Designs, Codes and Cryptography (2018)
Michels, M., Horster, P.: On the risk of disruption in several multiparty signature schemes. In: Kim, K., Matsumoto, T. (eds.) ASIACRYPT 1996. LNCS, vol. 1163, pp. 334–345. Springer, Heidelberg (1996). https://doi.org/10.1007/BFb0034859
Nakamoto, S.: Bitcoin- a peer-to-peer electronic cash system (2008)
Pedersen, T.P.: Non-interactive and information-theoretic secure verifiable secret sharing. In: Feigenbaum, J. (ed.) CRYPTO 1991. LNCS, vol. 576, pp. 129–140. Springer, Heidelberg (1992). https://doi.org/10.1007/3-540-46766-1_9
Poelstra, A.: Mimblewimble (2016). https://download.wpsoftware.net/bitcoin/wizardry/mimblewimble.pdf
Poelstra, A., Back, A., Friedenbach, M., Maxwell, G., Wuille, P.: Confidential assets. In: Zohar, A., et al. (eds.) Financial Cryptography and Data Security. LNCS, vol. 10958, pp. 43–63. Springer, Heidelberg (2019). https://doi.org/10.1007/978-3-662-58820-8_4
Ristenpart, T., Yilek, S.: The power of proofs-of-possession: securing multiparty signatures against rogue-key attacks. In: Naor, M. (ed.) EUROCRYPT 2007. LNCS, vol. 4515, pp. 228–245. Springer, Heidelberg (2007). https://doi.org/10.1007/978-3-540-72540-4_13
Ruffing, T., Thyagarajan, S., Ronge, V., Schroder, D.: (short paper) burning zerocoins for fun and for profit - a cryptographic denial-of-spending attack on the zerocoin protocol, pp. 116–119 (2018). https://doi.org/10.1109/CVCBT.2018.00023
Schnorr, C.P.: Efficient signature generation by smart cards. J. Cryptol. 4(3), 161–174 (1991)
Shamir, A.: How to share a secret. Commun. ACM 22(11), 612–613 (1979)
grin tech.org: Grin. https://github.com/mimblewimble. Accessed 21 May 2020
tlu.tarilabs.com: Mimblewimble multiparty bulletproof UTXO. http://tlu.tarilabs.com/protocols/mimblewimble-mp-bp-utxo/MainReport.html. Accessed 21 May 2020
Wood, G., et al.: Ethereum: a secure decentralised generalised transaction ledger. Ethereum Project Yellow Paper 151, 1–32 (2014)
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Appendices
A Compact Schnorr and BLS Signatures
The protocols of \(\mathtt {SIG}_{\mathtt {SCH}}\) and \(\mathtt {SIG}_{\mathtt {BLS}}\) are explained below.
B Improved Inner Product Argument with Strong Fiat Shamir Challenges
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Alupotha, J., Boyen, X., Foo, E. (2020). Compact Multi-Party Confidential Transactions. In: Krenn, S., Shulman, H., Vaudenay, S. (eds) Cryptology and Network Security. CANS 2020. Lecture Notes in Computer Science(), vol 12579. Springer, Cham. https://doi.org/10.1007/978-3-030-65411-5_21
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