Abstract
In the algebraic group model (AGM), an adversary has to return with each group element a linear representation with respect to input group elements. In many groups, it is easy to sample group elements obliviously without knowing such linear representations. Since the AGM does not model this, it can be used to prove the security of spurious knowledge assumptions. We show several well-known zk-SNARKs use such assumptions. We propose AGM with oblivious sampling (AGMOS), an AGM variant where the adversary can access an oracle that allows sampling group elements obliviously from some distribution. We show that AGM and AGMOS are different by studying the family of “total knowledge-of-exponent” assumptions, showing that they are all secure in the AGM, but most are not secure in the AGMOS if the DL holds. We show an important separation in the case of the KZG commitment scheme. We show that many known AGM reductions go through also in the AGMOS, assuming a novel falsifiable assumption \(\textrm{TOFR}\).
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Notes
- 1.
Let \(\hat{e}: \mathbb {G}_{1} \times \mathbb {G}_{2} \rightarrow \mathbb {G}_{T}\) be a bilinear pairing. Let the order of the groups be a prime p and denote \(\mathbb {F}= \mathbb {Z}_{p}\). We use the standard additive bracket notation, denoting a group element as \(z \cdot [1]_{\kappa } = [z]_{\kappa } \in \mathbb {G}_{\kappa }\), where \([1]_{\kappa }\) is a generator of an additive abelian group \(\mathbb {G}_{\kappa }\), by \([z]_{\kappa }\). We denote the pairing by \(\bullet : \mathbb {G}_{1} \times \mathbb {G}_{2} \rightarrow \mathbb {G}_{T}\).
- 2.
The actual reduction is slightly more complicated since we need to guarantee that \(V\) is a non-zero polynomial.
- 3.
One can prove the security of a concrete assumption or a concrete primitive/protocol. We will call all things we prove in the AGMOS assumptions instead of each time saying “an assumption or the security of a protocol”.
- 4.
One can extend AGMOS to allow arguing about adversarial outputs from \(\mathbb {G}_{T}\), but it is just our preference not to do so. See [23] for a discussion.
References
Abdolmaleki, B., Baghery, K., Lipmaa, H., Zajac, M.: A subversion-resistant SNARK. In: Takagi, T., Peyrin, T. (eds.) ASIACRYPT 2017, Part III. LNCS, vol. 10626, pp. 3–33. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-70700-6_1
Abdolmaleki, B., Lipmaa, H., Siim, J., Zajac, M.: On subversion-resistant SNARKs. J. Cryptol. 34(3), 17 (2021). https://doi.org/10.1007/s00145-021-09379-y
Bellare, M., Fuchsbauer, G., Scafuro, A.: NIZKs with an untrusted CRS: security in the face of parameter subversion. In: Cheon, J.H., Takagi, T. (eds.) ASIACRYPT 2016, Part II. LNCS, vol. 10032, pp. 777–804. Springer, Heidelberg (2016). https://doi.org/10.1007/978-3-662-53890-6_26
Boneh, D., Boyen, X., Goh, E.-J.: Hierarchical identity based encryption with constant size ciphertext. In: Cramer, R. (ed.) EUROCRYPT 2005. LNCS, vol. 3494, pp. 440–456. Springer, Heidelberg (2005). https://doi.org/10.1007/11426639_26
Boneh, D., Franklin, M.: Identity-based encryption from the weil pairing. In: Kilian, J. (ed.) CRYPTO 2001. LNCS, vol. 2139, pp. 213–229. Springer, Heidelberg (2001). https://doi.org/10.1007/3-540-44647-8_13
Boyen, X.: The uber-assumption family. In: Galbraith, S.D., Paterson, K.G. (eds.) Pairing 2008. LNCS, vol. 5209, pp. 39–56. Springer, Heidelberg (2008). https://doi.org/10.1007/978-3-540-85538-5_3
Brands, S.: Untraceable off-line cash in wallet with observers (extended abstract). In: Stinson, D.R. (ed.) CRYPTO 1993. LNCS, vol. 773, pp. 302–318. Springer, Heidelberg (1994). https://doi.org/10.1007/3-540-48329-2_26
Brier, E., Coron, J.-S., Icart, T., Madore, D., Randriam, H., Tibouchi, M.: Efficient indifferentiable hashing into ordinary elliptic curves. In: Rabin, T. (ed.) CRYPTO 2010. LNCS, vol. 6223, pp. 237–254. Springer, Heidelberg (2010). https://doi.org/10.1007/978-3-642-14623-7_13
Brown, D.R.L.: The exact security of ECDSA. Contributions to IEEE P1363a, January 2001. https://grouper.ieee.org/groups/1363/
Campanelli, M., Faonio, A., Fiore, D., Querol, A., Rodríguez, H.: Lunar: a toolbox for more efficient universal and updatable zkSNARKs and commit-and-prove extensions. Cryptology ePrint Archive, Report 2020/1069 (2020). https://eprint.iacr.org/2020/1069
Campanelli, M., Faonio, A., Fiore, D., Querol, A., Rodríguez, H.: Lunar: a toolbox for more efficient universal and updatable zkSNARKs and commit-and-prove extensions. In: Tibouchi, M., Wang, H. (eds.) ASIACRYPT 2021, Part III. LNCS, vol. 13092, pp. 3–33. Springer, Cham (2021). https://doi.org/10.1007/978-3-030-92078-4_1
Damgård, I.: Towards practical public key systems secure against chosen ciphertext attacks. In: Feigenbaum, J. (ed.) CRYPTO 1991. LNCS, vol. 576, pp. 445–456. Springer, Heidelberg (1992). https://doi.org/10.1007/3-540-46766-1_36
Danezis, G., Fournet, C., Groth, J., Kohlweiss, M.: Square span programs with applications to succinct NIZK arguments. In: Sarkar, P., Iwata, T. (eds.) ASIACRYPT 2014, Part I. LNCS, vol. 8873, pp. 532–550. Springer, Heidelberg (2014). https://doi.org/10.1007/978-3-662-45611-8_28
Dent, A.W.: Adapting the weaknesses of the random oracle model to the generic group model. In: Zheng, Y. (ed.) ASIACRYPT 2002. LNCS, vol. 2501, pp. 100–109. Springer, Heidelberg (2002). https://doi.org/10.1007/3-540-36178-2_6
Fischlin, M.: A note on security proofs in the generic model. In: Okamoto, T. (ed.) ASIACRYPT 2000. LNCS, vol. 1976, pp. 458–469. Springer, Heidelberg (2000). https://doi.org/10.1007/3-540-44448-3_35
Fischlin, M., Lehmann, A., Ristenpart, T., Shrimpton, T., Stam, M., Tessaro, S.: Random oracles with(out) programmability. In: Abe, M. (ed.) ASIACRYPT 2010. LNCS, vol. 6477, pp. 303–320. Springer, Heidelberg (2010). https://doi.org/10.1007/978-3-642-17373-8_18
Fouque, P.-A., Tibouchi, M.: Estimating the size of the image of deterministic hash functions to elliptic curves. In: Abdalla, M., Barreto, P.S.L.M. (eds.) LATINCRYPT 2010. LNCS, vol. 6212, pp. 81–91. Springer, Heidelberg (2010). https://doi.org/10.1007/978-3-642-14712-8_5
Fuchsbauer, G., Kiltz, E., Loss, J.: The algebraic group model and its applications. In: Shacham, H., Boldyreva, A. (eds.) CRYPTO 2018, Part II. LNCS, vol. 10992, pp. 33–62. Springer, Cham (2018). https://doi.org/10.1007/978-3-319-96881-0_2
Fuchsbauer, G., Plouviez, A., Seurin, Y.: Blind Schnorr signatures and signed ElGamal encryption in the algebraic group model. In: Canteaut, A., Ishai, Y. (eds.) EUROCRYPT 2020, Part II. LNCS, vol. 12106, pp. 63–95. Springer, Cham (2020). https://doi.org/10.1007/978-3-030-45724-2_3
Gabizon, A., Williamson, Z.J., Ciobotaru, O.: PLONK: permutations over lagrange-bases for oecumenical noninteractive arguments of knowledge. Cryptology ePrint Archive, Report 2019/953 (2019). https://eprint.iacr.org/2019/953
Ghoshal, A., Tessaro, S.: Tight state-restoration soundness in the algebraic group model. In: Malkin, T., Peikert, C. (eds.) CRYPTO 2021, Part III. LNCS, vol. 12827, pp. 64–93. Springer, Cham (2021). https://doi.org/10.1007/978-3-030-84252-9_3
Icart, T.: How to hash into elliptic curves. In: Halevi, S. (ed.) CRYPTO 2009. LNCS, vol. 5677, pp. 303–316. Springer, Heidelberg (2009). https://doi.org/10.1007/978-3-642-03356-8_18
Jager, T., Rupp, A.: The semi-generic group model and applications to pairing-based cryptography. In: Abe, M. (ed.) ASIACRYPT 2010. LNCS, vol. 6477, pp. 539–556. Springer, Heidelberg (2010). https://doi.org/10.1007/978-3-642-17373-8_31
Kate, A., Zaverucha, G.M., Goldberg, I.: Constant-size commitments to polynomials and their applications. In: Abe, M. (ed.) ASIACRYPT 2010. LNCS, vol. 6477, pp. 177–194. Springer, Heidelberg (2010). https://doi.org/10.1007/978-3-642-17373-8_11
Kohlweiss, M., Maller, M., Siim, J., Volkhov, M.: Snarky ceremonies. In: Tibouchi, M., Wang, H. (eds.) ASIACRYPT 2021, Part III. LNCS, vol. 13092, pp. 98–127. Springer, Cham (2021). https://doi.org/10.1007/978-3-030-92078-4_4
Lipmaa, H.: Progression-free sets and sublinear pairing-based non-interactive zero-knowledge arguments. In: Cramer, R. (ed.) TCC 2012. LNCS, vol. 7194, pp. 169–189. Springer, Heidelberg (2012). https://doi.org/10.1007/978-3-642-28914-9_10
Lipmaa, H.: Simulation-extractable ZK-SNARKs revisited. Technical report 2019/612, IACR, 31 May 2019. https://ia.cr/2019/612. Accessed 8 Feb 2020
Lipmaa, H.: A unified framework for non-universal SNARKs. In: Hanaoka, G., Shikata, J., Watanabe, Y. (eds.) PKC 2022, Part I. LNCS, vol. 13177, pp. 553–583. Springer, Heidelberg (2022). https://doi.org/10.1007/978-3-030-97121-2_20
Lipmaa, H., Siim, J., Parisella, R.: Algebraic group model with oblivious sampling. Technical report 2023/?, IACR, September 2023. https://eprint.iacr.org/2023/?
Maurer, U.M.: Abstract models of computation in cryptography (invited paper). In: Smart, N.P. (ed.) Cryptography and Coding 2005. LNCS, vol. 3796, pp. 1–12. Springer, Heidelberg (Dec (2005). https://doi.org/10.1007/11586821_1
Nielsen, J.B.: Separating random oracle proofs from complexity theoretic proofs: the non-committing encryption case. In: Yung, M. (ed.) CRYPTO 2002. LNCS, vol. 2442, pp. 111–126. Springer, Heidelberg (2002). https://doi.org/10.1007/3-540-45708-9_8
Rotem, L.: Revisiting the uber assumption in the algebraic group model: fine-grained bounds in hidden-order groups and improved reductions in bilinear groups. In: Dachman-Soled, D. (ed.) ITC 2022. LIPIcs, vol. 230, pp. 13:1–13:13. Cambridge, MA, USA, 5–7 July 2022. https://doi.org/10.4230/LIPIcs.ITC.2022.13
Rotem, L., Segev, G.: Algebraic distinguishers: from discrete logarithms to decisional uber assumptions. In: Pass, R., Pietrzak, K. (eds.) TCC 2020, Part III. LNCS, vol. 12552, pp. 366–389. Springer, Cham (2020). https://doi.org/10.1007/978-3-030-64381-2_13
Schnorr, C.P.: Efficient signature generation by smart cards. J. Cryptol. 4(3), 161–174 (1991). https://doi.org/10.1007/BF00196725
Shoup, V.: Lower bounds for discrete logarithms and related problems. In: Fumy, W. (ed.) EUROCRYPT 1997. LNCS, vol. 1233, pp. 256–266. Springer, Heidelberg (1997). https://doi.org/10.1007/3-540-69053-0_18
Stern, J., Pointcheval, D., Malone-Lee, J., Smart, N.P.: Flaws in applying proof methodologies to signature schemes. In: Yung, M. (ed.) CRYPTO 2002. LNCS, vol. 2442, pp. 93–110. Springer, Heidelberg (2002). https://doi.org/10.1007/3-540-45708-9_7
Wahby, R.S., Boneh, D.: Fast and simple constant-time hashing to the BLS12-381 elliptic curve. IACR TCHES 2019(4), 154–179 (2019). https://doi.org/10.13154/tches.v2019.i4.154-179, https://tches.iacr.org/index.php/TCHES/article/view/8348
Zhandry, M.: To label, or not to label (in generic groups). In: Dodis, Y., Shrimpton, T. (eds.) CRYPTO 2022. LNCS, vol. 13509, pp. 66–96. Springer, Heidelberg (2022). https://doi.org/10.1007/978-3-031-15982-4_3
Zhang, C., Zhou, H.S., Katz, J.: An Analysis of the Algebraic Group Model, pp. 310–322 (2022)
Acknowledgment
We thank Markulf Kohlweiss and anonymous reviewers for helpful comments.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2023 International Association for Cryptologic Research
About this paper
Cite this paper
Lipmaa, H., Parisella, R., Siim, J. (2023). Algebraic Group Model with Oblivious Sampling. In: Rothblum, G., Wee, H. (eds) Theory of Cryptography. TCC 2023. Lecture Notes in Computer Science, vol 14372. Springer, Cham. https://doi.org/10.1007/978-3-031-48624-1_14
Download citation
DOI: https://doi.org/10.1007/978-3-031-48624-1_14
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-031-48623-4
Online ISBN: 978-3-031-48624-1
eBook Packages: Computer ScienceComputer Science (R0)