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2024 | OriginalPaper | Buchkapitel

Anamorphic Encryption: New Constructions and Homomorphic Realizations

verfasst von : Dario Catalano, Emanuele Giunta, Francesco Migliaro

Erschienen in: Advances in Cryptology – EUROCRYPT 2024

Verlag: Springer Nature Switzerland

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Abstract

The elegant paradigm of Anamorphic Encryption (Persiano et al., Eurocrypt 2022) considers the question of establishing a private communication in a world controlled by a dictator. The challenge is to allow two users, sharing some secret anamorphic key, to exchange covert messages without the dictator noticing, even when the latter has full access to the regular secret keys. Over the last year several works considered this question and proposed constructions, novel extensions and strengthened definitions.

In this work we make progress on the study of this primitive in three main directions. First, we show that two general and well established encryption paradigms, namely hybrid encryption and the IBE-to-CCA transform, admit very simple and natural anamorphic extensions. Next, we show that anamorphism, far from being a phenomenon isolated to “basic” encryption schemes, extends also to homomorphic encryption. We show that some existing homomorphic schemes, (and most notably the fully homomorphic one by Gentry, Sahai and Waters) can be made anamorphic, while retaining their homomorphic properties both with respect to the regular and the covert message.

Finally we refine the notion of anamorphic encryption by envisioning the possibility of splitting the anamorphic key into an encryption component (that only allows to encrypt covert messages) and a decryption component. This makes possible for a receiver to set up several, independent, covert channels associated with a single covert key.

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Vorheriges Kapitel Anamorphic Encryption, Revisited

Nächstes Kapitel Fully Homomorphic Encryption Beyond IND-CCA1 Security: Integrity Through Verifiability

As argued in [BGHM23] the notion of robustness is relevant for security: a dictator could try to trick receivers to expose their possession of a double key by sending them regular (i.e. not containing any covert message) ciphertext and monitor the reaction.

To better illustrate our basic ideas, we ignore the flattening step [GSW13] here.

We remark here that our NY-based construction achieves this nice property as well.

We stress that the definitions given in [KPP+23b] differs from the original definition from [PPY22] in some small details, that make the former more readily suitable to our setting. We refer the interested reader to [KPP+23b] for an in-depth discussion of these differences.

[ADKL19]

Ananth, P., Deshpande, A., Kalai, Y.T., Lysyanskaya, A.: Fully Homomorphic NIZK and NIWI Proofs. In: Hofheinz, D., Rosen, A. (eds.) TCC 2019, Part II. LNCS, vol. 11892, pp. 356–385. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-36033-7_14CrossRef

[BCHK07]

Boneh, D., Canetti, R., Halevi, S., Katz, J.: Chosen-ciphertext security from identity-based encryption. SIAM J. Comput. 36(5), 1301–1328 (2007)MathSciNetCrossRef

[BG84]

Blum, M., Goldwasser, S.: An efficient probabilistic public-key encryption scheme which hides all partial information. In: Blakley, G.R., Chaum, D. (eds.) CRYPTO 1984. LNCS, vol. 196, pp. 289–299. Springer, Heidelberg (1985). https://doi.org/10.1007/3-540-39568-7_23CrossRef

[BGHM23]

Banfi, F., Gegier, K., Hirt, M., Maurer, U.: Anamorphic encryption, revisited. Cryptology ePrint Archive, Report 2023/249 (2023). https://eprint.iacr.org/2023/249

[Bla94]

Blaze, M.: Protocol failure in the escrowed encryption standard. In: Denning, D.E., Pyle, R., Ganesan, R., Sandhu, R.S. (eds.) ACM CCS 94, pp. 59–67. ACM Press (1994)

[CDNO97]

Canetti, R., Dwork, C., Naor, M., Ostrovsky, R.: Deniable encryption. In: Kaliski, B.S. (ed.) CRYPTO 1997. LNCS, vol. 1294, pp. 90–104. Springer, Heidelberg (1997). https://doi.org/10.1007/BFb0052229CrossRef

[CS98]

Cramer, R., Shoup, V.: A practical public key cryptosystem provably secure against adaptive chosen ciphertext attack. In: Krawczyk, H. (ed.) CRYPTO 1998. LNCS, vol. 1462, pp. 13–25. Springer, Heidelberg (1998). https://doi.org/10.1007/BFb0055717CrossRef

[FY95]

Frankel, Y., Yung, M.: Escrow encryption systems visited: attacks, analysis and designs. In: Coppersmith, D. (ed.) CRYPTO 1995. LNCS, vol. 963, pp. 222–235. Springer, Heidelberg (1995). https://doi.org/10.1007/3-540-44750-4_18CrossRef

[Gen09]

Gentry, C.: Fully homomorphic encryption using ideal lattices. In: Mitzenmacher, M. (ed.) 41st ACM STOC, pp. 169–178. ACM Press (2009)

[GSW13]

Gentry, C., Sahai, A., Waters, B.: Homomorphic Encryption from Learning with Errors: Conceptually-Simpler, Asymptotically-Faster, Attribute-Based. In: Canetti, R., Garay, J.A. (eds.) CRYPTO 2013, Part I. LNCS, vol. 8042, pp. 75–92. Springer, Heidelberg (2013). https://doi.org/10.1007/978-3-642-40041-4_5CrossRef

[IL89]

Impagliazzo, R., Luby, M.: One-way functions are essential for complexity based cryptography (extended abstract). In: 30th FOCS, pp. 230–235. IEEE Computer Society Press (1989)

[ILL89]

Impagliazzo, R., Levin, L.A., Luby, M.: Pseudo-random generation from one-way functions (extended abstracts). In: 21st ACM STOC, pp. 12–24. ACM Press (1989)

[KPP+23a]

Kutylowski, M., Persiano, G., Phan, D.H., Yung, M., Zawada, M.: Anamorphic signatures: secrecy from a dictator who only permits authentication! In: Handschuh, H., Lysyanskaya, A. (eds.) CRYPTO 2023, Part II. LNCS, vol. 14082, pp. 759–790. Springer, Heidelberg (2023). https://doi.org/10.1007/978-3-031-38545-2_25CrossRef

[KPP+23b]

Kutylowski, M., Persiano, G., Phan, D.H., Yung, M., Zawada, M.: The self-anti-censorship nature of encryption: on the prevalence of anamorphic cryptography. Proc. Priv. Enhancing Technol. 2023(4), 170–183 (2023)CrossRef

[Mic93]

Micali, S.: Fair public-key cryptosystems. In: Brickell, E.F. (ed.) CRYPTO 1992. LNCS, vol. 740, pp. 113–138. Springer, Heidelberg (1993). https://doi.org/10.1007/3-540-48071-4_9CrossRef

[Möl04]

Möller, B.: A public-key encryption scheme with pseudo-random ciphertexts. In: Samarati, P., Ryan, P., Gollmann, D., Molva, R. (eds.) ESORICS 2004. LNCS, vol. 3193, pp. 335–351. Springer, Heidelberg (2004). https://doi.org/10.1007/978-3-540-30108-0_21CrossRef

[MP12]

Micciancio, D., Peikert, C.: Trapdoors for lattices: simpler, tighter, faster, smaller. In: Pointcheval, D., Johansson, T. (eds.) EUROCRYPT 2012. LNCS, vol. 7237, pp. 700–718. Springer, Heidelberg (2012). https://doi.org/10.1007/978-3-642-29011-4_41CrossRef

[NY90]

Naor, M., Yung, M.: Public-key cryptosystems provably secure against chosen ciphertext attacks. In: 22nd ACM STOC, pp. 427–437. ACM Press (1990)

[PPY22]

Persiano, G., Phan, D.H., Yung, M.: Anamorphic encryption: private communication against a dictator. In: Dunkelman, O., Dziembowski, S. (eds.) EUROCRYPT 2022, Part II. LNCS, vol. 13276, pp. 34–63. Springer, Heidelberg (2022). https://doi.org/10.1007/978-3-031-07085-3_2CrossRef

[Sah99]

Sahai, A.: Non-malleable non-interactive zero knowledge and adaptive chosen-ciphertext security. In: 40th FOCS, pp. 543–553. IEEE Computer Society Press (1999)

[Sho00]

Shoup, V.: Using hash functions as a hedge against chosen ciphertext attack. In: Preneel, B. (ed.) EUROCRYPT 2000. LNCS, vol. 1807, pp. 275–288. Springer, Heidelberg (2000). https://doi.org/10.1007/3-540-45539-6_19CrossRef

[vH04]

von Ahn, L., Hopper, N.J.: Public-key steganography. In: Cachin, C., Camenisch, J.L. (eds.) EUROCRYPT 2004. LNCS, vol. 3027, pp. 323–341. Springer, Heidelberg (2004). https://doi.org/10.1007/978-3-540-24676-3_20CrossRef

[WCHY23]

Wang, Y., Chen, R., Huang, X., Yung, M.: Sender-anamorphic encryption reformulated: Achieving robust and generic constructions. In: Guo, J., Steinfeld, R. (eds.) ASIACRYPT 2023, Part VI. LNCS, vol. 14443, pp. 135–167. Springer, Cham (2023). https://doi.org/10.1007/978-981-99-8736-8_5CrossRef

[YY96]

Young, A., Yung, M.: The dark side of “Black-Box’’ cryptography or: should we trust capstone? In: Koblitz, N. (ed.) CRYPTO 1996. LNCS, vol. 1109, pp. 89–103. Springer, Heidelberg (1996). https://doi.org/10.1007/3-540-68697-5_8CrossRef

[YY97]

Young, A., Yung, M.: The prevalence of kleptographic attacks on discrete-log based cryptosystems. In: Kaliski, B.S. (ed.) CRYPTO 1997. LNCS, vol. 1294, pp. 264–276. Springer, Heidelberg (1997). https://doi.org/10.1007/BFb0052241CrossRef

Titel: Anamorphic Encryption: New Constructions and Homomorphic Realizations
verfasst von: Dario Catalano
Emanuele Giunta
Francesco Migliaro
Verlag: Springer Nature Switzerland
Buch: Advances in Cryptology – EUROCRYPT 2024
Print ISBN: 978-3-031-58722-1

Electronic ISBN: 978-3-031-58723-8

Copyright-Jahr: 2024
DOI: https://doi.org/10.1007/978-3-031-58723-8_2

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