메뉴 건너뛰기




Volumn 8270 LNCS, Issue PART 2, 2013, Pages 441-463

Secure two-party computation with reusable bit-commitments, via a cut-and-choose with forge-and-lose technique (extended abstract)

Author keywords

cut and choose; forge and lose; garbled circuits; homomorphic bit commitments with trapdoor; secure two party computation

Indexed keywords

CUT-AND-CHOOSE; FORGE-AND-LOSE; GARBLED CIRCUITS; HOMOMORPHIC BIT-COMMITMENTS WITH TRAPDOOR; SECURE TWO-PARTY COMPUTATIONS;

EID: 84892423216     PISSN: 03029743     EISSN: 16113349     Source Type: Book Series    
DOI: 10.1007/978-3-642-42045-0_23     Document Type: Conference Paper
Times cited : (28)

References (69)
  • 1
    • 48249089807 scopus 로고    scopus 로고
    • Recommendation for Key Management - Part 1: General
    • (Revision 3) U.S. Department of Commerce, NIST-ITL-CSD July
    • Barker, E., Barker, W., Burr, W., Polk, W., Smid, M.: Recommendation for Key Management - Part 1: General (Revision 3) - NIST Special Publication 800-57. U.S. Department of Commerce, NIST-ITL-CSD (July 2012)
    • (2012) NIST Special Publication 800-57
    • Barker, E.1    Barker, W.2    Burr, W.3    Polk, W.4    Smid, M.5
  • 3
    • 33745994328 scopus 로고    scopus 로고
    • Short Non-Interactive Cryptographic Proofs
    • Boyar, J., Damgård, I., Peralta, R.: Short Non-Interactive Cryptographic Proofs. Journal of Cryptology 13(4), 449-472 (2000)
    • (2000) Journal of Cryptology , vol.13 , Issue.4 , pp. 449-472
    • Boyar, J.1    Damgård, I.2    Peralta, R.3
  • 4
    • 0029702967 scopus 로고    scopus 로고
    • Correlated pseudorandomness and the complexity of private computations
    • ACM, New York
    • Beaver, D.: Correlated pseudorandomness and the complexity of private computations. In: Proc. STOC 1996, pp. 479-488. ACM, New York (1996)
    • (1996) Proc. STOC 1996 , pp. 479-488
    • Beaver, D.1
  • 5
    • 84869382999 scopus 로고    scopus 로고
    • Foundations of garbled circuits
    • ACM, New York
    • Bellare, M., Hoang, V.T., Rogaway, P.: Foundations of garbled circuits. In: Proc. CCS 2012, pp. 784-796. ACM, New York (2012),
    • (2012) Proc. CCS 2012 , pp. 784-796
    • Bellare, M.1    Hoang, V.T.2    Rogaway, P.3
  • 7
    • 17744380057 scopus 로고
    • Coin flipping by telephone a protocol for solving impossible problems
    • Blum, M.: Coin flipping by telephone a protocol for solving impossible problems. SIGACT News 15(1), 23-27 (1983)
    • (1983) SIGACT News , vol.15 , Issue.1 , pp. 23-27
    • Blum, M.1
  • 8
    • 0025137207 scopus 로고
    • The round complexity of secure protocols
    • ACM, New York
    • Beaver, D., Micali, S., Rogaway, P.: The round complexity of secure protocols. In: Proc. STOC 1990, pp. 503-513. ACM, New York (1990)
    • (1990) Proc. STOC 1990 , pp. 503-513
    • Beaver, D.1    Micali, S.2    Rogaway, P.3
  • 9
    • 84892383451 scopus 로고    scopus 로고
    • A Framework for Interactive Argument Systems using Quasigroupic Homorphic Commitment
    • Report 2006/472
    • Brandão, L.T.A.N.: A Framework for Interactive Argument Systems using Quasigroupic Homorphic Commitment. Cryptology ePrint Archive, Report 2006/472 (2006)
    • (2006) Cryptology ePrint Archive
    • Brandão, L.T.A.N.1
  • 11
    • 0000731055 scopus 로고    scopus 로고
    • Security and Composition of Multiparty Cryptographic Protocols
    • Canetti, R.: Security and Composition of Multiparty Cryptographic Protocols. Journal of Cryptology 13(1), 143-202 (2000),
    • (2000) Journal of Cryptology , vol.13 , Issue.1 , pp. 143-202
    • Canetti, R.1
  • 13
    • 84957649042 scopus 로고
    • Committed Oblivious Transfer and Private Multi-party Computation
    • Coppersmith, D. (ed.) CRYPTO 1995. Springer, Heidelberg
    • Crépeau, C., van de Graaf, J., Tapp, A.: Committed Oblivious Transfer and Private Multi-party Computation. In: Coppersmith, D. (ed.) CRYPTO 1995. LNCS, vol. 963, pp. 110-123. Springer, Heidelberg (1995)
    • (1995) LNCS , vol.963 , pp. 110-123
    • Crépeau, C.1    Van De Graaf, J.2    Tapp, A.3
  • 14
    • 0036038991 scopus 로고    scopus 로고
    • Universally composable two-party and multi-party secure computation
    • ACM, New York
    • Canetti, R., Lindell, Y., Ostrovsky, R., Sahai, A.: Universally composable two-party and multi-party secure computation. In: Proc. STOC 2002, pp. 494-503. ACM, New York (2002),
    • (2002) Proc. STOC 2002 , pp. 494-503
    • Canetti, R.1    Lindell, Y.2    Ostrovsky, R.3    Sahai, A.4
  • 17
  • 18
    • 84883362608 scopus 로고    scopus 로고
    • MiniLEGO: Efficient Secure Two-Party Computation from General Assumptions
    • Johansson, T., Nguyen, P.Q. (eds.) EUROCRYPT 2013. Springer, Heidelberg
    • Frederiksen, T.K., Jakobsen, T.P., Nielsen, J.B., Nordholt, P.S., Orlandi, C.: MiniLEGO: Efficient Secure Two-Party Computation from General Assumptions. In: Johansson, T., Nguyen, P.Q. (eds.) EUROCRYPT 2013. LNCS, vol. 7881, pp. 537-556. Springer, Heidelberg (2013),
    • (2013) LNCS , vol.7881 , pp. 537-556
    • Frederiksen, T.K.1    Jakobsen, T.P.2    Nielsen, J.B.3    Nordholt, P.S.4    Orlandi, C.5
  • 20
    • 84879859791 scopus 로고    scopus 로고
    • Fast and Maliciously Secure Two-Party Computation Using the GPU
    • Jacobson, M., Locasto, M., Mohassel, P., Safavi-Naini, R. (eds.) ACNS 2013. Springer, Heidelberg
    • Frederiksen, T.K., Nielsen, J.B.: Fast and Maliciously Secure Two-Party Computation Using the GPU. In: Jacobson, M., Locasto, M., Mohassel, P., Safavi-Naini, R. (eds.) ACNS 2013. LNCS, vol. 7954, pp. 339-356. Springer, Heidelberg (2013)
    • (2013) LNCS , vol.7954 , pp. 339-356
    • Frederiksen, T.K.1    Nielsen, J.B.2
  • 22
    • 0021555016 scopus 로고
    • A "Paradoxical" Solution To The Signature Problem
    • IEEE Computer Society
    • Goldwasser, S., Micali, S., Rivest, R.L.: A "Paradoxical" Solution To The Signature Problem. In: Proc. FOCS 1984, pp. 441-448. IEEE Computer Society (1984)
    • (1984) Proc. FOCS 1984 , pp. 441-448
    • Goldwasser, S.1    Micali, S.2    Rivest, R.L.3
  • 23
    • 44449160882 scopus 로고    scopus 로고
    • Efficient Two Party and Multi Party Computation Against Covert Adversaries
    • Smart, N. (ed.) EUROCRYPT 2008. Springer, Heidelberg
    • Goyal, V., Mohassel, P., Smith, A.: Efficient Two Party and Multi Party Computation Against Covert Adversaries. In: Smart, N. (ed.) EUROCRYPT 2008. LNCS, vol. 4965, pp. 289-306. Springer, Heidelberg (2008)
    • (2008) LNCS , vol.4965 , pp. 289-306
    • Goyal, V.1    Mohassel, P.2    Smith, A.3
  • 25
    • 78649820323 scopus 로고    scopus 로고
    • Basic Applications
    • Chapter 7 (General Cryptographic Protocols). Cambridge University Press, New York
    • Goldreich, O.: Foundations of Cryptography: Volume 2, Basic Applications, Chapter 7 (General Cryptographic Protocols). Cambridge University Press, New York (2004)
    • (2004) Foundations of Cryptography , vol.2
    • Goldreich, O.1
  • 26
    • 84914127581 scopus 로고    scopus 로고
    • Faster Secure Two-Party Computation Using Garbled Circuits
    • USENIX Association
    • Huang, Y., Evans, D., Katz, J., Malka, L.: Faster Secure Two-Party Computation Using Garbled Circuits. In: Proc. SEC 2011. USENIX Association (2011)
    • (2011) Proc. SEC 2011
    • Huang, Y.1    Evans, D.2    Katz, J.3    Malka, L.4
  • 27
    • 84878348015 scopus 로고    scopus 로고
    • Quid-Pro-Quo-tocols: Strengthening Semi-Honest Protocols with Dual Execution
    • IEEE Computer Society, Washington
    • Huang, Y., Katz, J., Evans, D.: Quid-Pro-Quo-tocols: Strengthening Semi-Honest Protocols with Dual Execution. In: Proc. S&P 2012, pp. 272-284. IEEE Computer Society, Washington (2012)
    • (2012) Proc. S&P 2012 , pp. 272-284
    • Huang, Y.1    Katz, J.2    Evans, D.3
  • 28
    • 84884477218 scopus 로고    scopus 로고
    • Efficient Secure Two-Party Computation Using Symmetric Cut-and-Choose
    • Canetti, R., Garay, J.A. (eds.) CRYPTO 2013, Part II. Springer, Heidelberg
    • Huang, Y., Katz, J., Evans, D.: Efficient Secure Two-Party Computation Using Symmetric Cut-and-Choose. In: Canetti, R., Garay, J.A. (eds.) CRYPTO 2013, Part II. LNCS, vol. 8043, pp. 18-35. Springer, Heidelberg (2013),
    • (2013) LNCS , vol.8043 , pp. 18-35
    • Huang, Y.1    Katz, J.2    Evans, D.3
  • 30
    • 24144457853 scopus 로고    scopus 로고
    • Extending Oblivious Transfers Efficiently
    • Boneh, D. (ed.) CRYPTO 2003. Springer, Heidelberg
    • Ishai, Y., Kilian, J., Nissim, K., Petrank, E.: Extending Oblivious Transfers Efficiently. In: Boneh, D. (ed.) CRYPTO 2003. LNCS, vol. 2729, pp. 145-161. Springer, Heidelberg (2003)
    • (2003) LNCS , vol.2729 , pp. 145-161
    • Ishai, Y.1    Kilian, J.2    Nissim, K.3    Petrank, E.4
  • 31
    • 38049136533 scopus 로고    scopus 로고
    • Efficient Two-Party Secure Computation on Committed Inputs
    • Naor, M. (ed.) EUROCRYPT 2007. Springer, Heidelberg
    • Jarecki, S., Shmatikov, V.: Efficient Two-Party Secure Computation on Committed Inputs, In: Naor, M. (ed.) EUROCRYPT 2007. LNCS, vol. 4515, pp. 97-114. Springer, Heidelberg (2007)
    • (2007) LNCS , vol.4515 , pp. 97-114
    • Jarecki, S.1    Shmatikov, V.2
  • 32
    • 79957989657 scopus 로고    scopus 로고
    • Ph.D. thesis, Technische Universiteit Eindhoven, Netherlands
    • Kiraz, M.S.: Secure and Fair Two-Party Computation. Ph.D. thesis, Technische Universiteit Eindhoven, Netherlands (2008)
    • (2008) Secure and Fair Two-Party Computation
    • Kiraz, M.S.1
  • 33
    • 84866677530 scopus 로고    scopus 로고
    • Improved Secure Two-Party Computation via Information-Theoretic Garbled Circuits
    • Visconti, I., De Prisco, R. (eds.) SCN 2012. Springer, Heidelberg
    • Kolesnikov, V., Kumaresan, R.: Improved Secure Two-Party Computation via Information-Theoretic Garbled Circuits. In: Visconti, I., De Prisco, R. (eds.) SCN 2012. LNCS, vol. 7485, pp. 205-221. Springer, Heidelberg (2012)
    • (2012) LNCS , vol.7485 , pp. 205-221
    • Kolesnikov, V.1    Kumaresan, R.2
  • 34
    • 73349105896 scopus 로고    scopus 로고
    • Advances and impact of secure function evaluation
    • Kolesnikov, V.: Advances and impact of secure function evaluation. Bell Labs Technical Journal 14(3), 187-192 (2009)
    • (2009) Bell Labs Technical Journal , vol.14 , Issue.3 , pp. 187-192
    • Kolesnikov, V.1
  • 36
    • 43149106725 scopus 로고    scopus 로고
    • An Efficient Protocol for Fair Secure Two-Party Computation
    • Malkin, T. (ed.) CT-RSA 2008. Springer, Heidelberg
    • Kiraz, M.S., Schoenmakers, B.: An Efficient Protocol for Fair Secure Two-Party Computation. In: Malkin, T. (ed.) CT-RSA 2008. LNCS, vol. 4964, pp. 88-105. Springer, Heidelberg (2008)
    • (2008) LNCS , vol.4964 , pp. 88-105
    • Kiraz, M.S.1    Schoenmakers, B.2
  • 37
    • 49049099825 scopus 로고    scopus 로고
    • Improved Garbled Circuit: Free XOR Gates and Applications
    • Aceto, L., Damgård, I., Goldberg, L.A., Halldórsson, M.M., Ingólfsdóttir, A., Walukiewicz, I. (eds.) ICALP 2008, Part II. Springer, Heidelberg
    • Kolesnikov, V., Schneider, T.: Improved Garbled Circuit: Free XOR Gates and Applications. In: Aceto, L., Damgård, I., Goldberg, L.A., Halldórsson, M.M., Ingólfsdóttir, A., Walukiewicz, I. (eds.) ICALP 2008, Part II. LNCS, vol. 5126, pp. 486-498. Springer, Heidelberg (2008)
    • (2008) LNCS , vol.5126 , pp. 486-498
    • Kolesnikov, V.1    Schneider, T.2
  • 38
    • 84889076745 scopus 로고    scopus 로고
    • Billion-gate secure computation with malicious adversaries
    • USENIX Association
    • Kreuter, B., Shelat, A., Shen, C.-H.: Billion-gate secure computation with malicious adversaries. In: Proc. Security 2012, pp. 285-300. USENIX Association (2012),
    • (2012) Proc. Security 2012 , pp. 285-300
    • Kreuter, B.1    Shelat, A.2    Shen, C.-H.3
  • 40
    • 4544235438 scopus 로고    scopus 로고
    • Parallel Coin-Tossing and Constant-Round Secure Two-Party Computation
    • Lindell, Y.: Parallel Coin-Tossing and Constant-Round Secure Two-Party Computation. Journal of Cryptology 16(3), 143-184 (2003),
    • (2003) Journal of Cryptology , vol.16 , Issue.3 , pp. 143-184
    • Lindell, Y.1
  • 42
    • 84884490479 scopus 로고    scopus 로고
    • Fast Cut-and-Choose Based Protocols for Malicious and Covert Adversaries
    • Canetti, R., Garay, J.A. (eds.) CRYPTO 2013, Part II. Springer, Heidelberg
    • Lindell, Y.: Fast Cut-and-Choose Based Protocols for Malicious and Covert Adversaries. In: Canetti, R., Garay, J.A. (eds.) CRYPTO 2013, Part II. LNCS, vol. 8043; pp. 1-17. Springer, Heidelberg (2013),
    • (2013) LNCS , vol.8043 , pp. 1-17
    • Lindell, Y.1
  • 44
    • 33746437508 scopus 로고    scopus 로고
    • Privacy Preserving Data Mining
    • Lindell, Y., Pinkas, B.: Privacy Preserving Data Mining. Journal of Cryptology 15(3), 177-206 (2002)
    • (2002) Journal of Cryptology , vol.15 , Issue.3 , pp. 177-206
    • Lindell, Y.1    Pinkas, B.2
  • 45
    • 38049136534 scopus 로고    scopus 로고
    • An Efficient Protocol for Secure Two-Party Computation in the Presence of Malicious Adversaries
    • Naor, M. (ed.) EUROCRYPT 2007. Springer, Heidelberg
    • Lindell, Y., Pinkas, B.: An Efficient Protocol for Secure Two-Party Computation in the Presence of Malicious Adversaries. In: Naor, M. (ed.) EUROCRYPT 2007. LNCS, vol. 4515, pp. 52-78. Springer, Heidelberg (2007),
    • (2007) LNCS , vol.4515 , pp. 52-78
    • Lindell, Y.1    Pinkas, B.2
  • 47
    • 64249101946 scopus 로고    scopus 로고
    • A Proof of Security of Yao's Protocol for Two-Party Computation
    • Lindell, Y., Pinkas, B.: A Proof of Security of Yao's Protocol for Two-Party Computation. Journal of Cryptology 22(2), 161-188 (2009)
    • (2009) Journal of Cryptology , vol.22 , Issue.2 , pp. 161-188
    • Lindell, Y.1    Pinkas, B.2
  • 48
    • 79953241261 scopus 로고    scopus 로고
    • Secure two-party computation via cut-and-choose oblivious transfer
    • Ishai, Y. (ed.) TCC 2011. Springer, Heidelberg
    • Lindell, Y., Pinkas, B.: Secure two-party computation via cut-and-choose oblivious transfer. In: Ishai, Y. (ed.) TCC 2011. LNCS, vol. 6597, pp. 329-346. Springer, Heidelberg (2011),
    • (2011) LNCS , vol.6597 , pp. 329-346
    • Lindell, Y.1    Pinkas, B.2
  • 50
    • 33745843587 scopus 로고    scopus 로고
    • Efficiency Tradeoffs for Malicious Two-Party Computation
    • Yung, M., Dodis, Y., Kiayias, A., Malkin, T. (eds.) PKC 2006. Springer, Heidelberg
    • Mohassel, P., Franklin, M.K.: Efficiency Tradeoffs for Malicious Two-Party Computation. In: Yung, M., Dodis, Y., Kiayias, A., Malkin, T. (eds.) PKC 2006. LNCS, vol. 3958, pp. 458-473. Springer, Heidelberg (2006)
    • (2006) LNCS , vol.3958 , pp. 458-473
    • Mohassel, P.1    Franklin, M.K.2
  • 51
    • 84865506559 scopus 로고    scopus 로고
    • A New Approach to Practical Active-Secure Two-Party Computation
    • Safavi-Naini, R., Canetti, R. (eds.) CRYPTO 2012. Springer, Heidelberg
    • Nielsen, J.B., Nordholt, P.S., Orlandi, C., Burra, S.S.: A New Approach to Practical Active-Secure Two-Party Computation. In: Safavi-Naini, R., Canetti, R. (eds.) CRYPTO 2012. LNCS, vol. 7417, pp. 681-700. Springer, Heidelberg (2012),
    • (2012) LNCS , vol.7417 , pp. 681-700
    • Nielsen, J.B.1    Nordholt, P.S.2    Orlandi, C.3    Burra, S.S.4
  • 53
    • 70350634167 scopus 로고    scopus 로고
    • LEGO for Two-Party Secure Computation
    • Reingold, O. (ed.) TCC 2009. Springer, Heidelberg
    • Nielsen, J.B., Orlandi, C.: LEGO for Two-Party Secure Computation. In: Reingold, O. (ed.) TCC 2009. LNCS, vol. 5444, pp. 368-386. Springer, Heidelberg (2009),
    • (2009) LNCS , vol.5444 , pp. 368-386
    • Nielsen, J.B.1    Orlandi, C.2
  • 55
    • 64049119146 scopus 로고    scopus 로고
    • Efficient oblivious transfer protocols
    • SIAM, Philadelphia
    • Naor, M., Pinkas, B.: Efficient oblivious transfer protocols. In: SODA 2001, pp. 448-457. SIAM, Philadelphia (2001)
    • (2001) SODA 2001 , pp. 448-457
    • Naor, M.1    Pinkas, B.2
  • 56
    • 84883898504 scopus 로고    scopus 로고
    • Privacy preserving auctions and mechanism design
    • ACM, New York
    • Naor, M., Pinkas, B., Sumner, R.: Privacy preserving auctions and mechanism design. In: Proc. EC 1999, pp. 129-139. ACM, New York (1999)
    • (1999) Proc. EC 1999 , pp. 129-139
    • Naor, M.1    Pinkas, B.2    Sumner, R.3
  • 58
    • 35248883427 scopus 로고    scopus 로고
    • Fair Secure Two-Party Computation
    • Biham, E. (ed.) EUROCRYPT 2003. Springer, Heidelberg
    • Pinkas, B.: Fair Secure Two-Party Computation. In: Biham, E. (ed.) EUROCRYPT 2003. LNCS, vol. 2656, pp. 647-647. Springer, Heidelberg (2003)
    • (2003) LNCS , vol.2656 , pp. 647-647
    • Pinkas, B.1
  • 59
    • 72449131818 scopus 로고    scopus 로고
    • Secure Two-Party Computation Is Practical
    • Matsui, M. (ed.) ASIACRYPT 2009. Springer, Heidelberg
    • Pinkas, B., Schneider, T., Smart, N., Williams, S.: Secure Two-Party Computation Is Practical. In: Matsui, M. (ed.) ASIACRYPT 2009. LNCS, vol. 5912, pp. 250-267. Springer, Heidelberg (2009),
    • (2009) LNCS , vol.5912 , pp. 250-267
    • Pinkas, B.1    Schneider, T.2    Smart, N.3    Williams, S.4
  • 61
    • 77953754678 scopus 로고
    • Technical Report TR-81, Harvard University, Aiken Computation Lab, Cambridge, MA
    • Rabin, M.O.: How to exchange secrets with oblivious transfer. Technical Report TR-81, Harvard University, Aiken Computation Lab, Cambridge, MA (1981),
    • (1981) How to Exchange Secrets with Oblivious Transfer
    • Rabin, M.O.1
  • 62
    • 84880890468 scopus 로고    scopus 로고
    • See typesetted version in Report 2005/187
    • See typesetted version in Cryptology ePrint Archive, Report 2005/187
    • Cryptology ePrint Archive
  • 63
    • 79958017670 scopus 로고    scopus 로고
    • Two-Output Secure Computation with Malicious Adversaries
    • Paterson, K.G. (ed.) EUROCRYPT 2011. Springer, Heidelberg
    • Shelat, A., Shen, C.-H.: Two-Output Secure Computation with Malicious Adversaries. In: Paterson, K.G. (ed.) EUROCRYPT 2011. LNCS, vol. 6632, pp. 386-405. Springer, Heidelberg (2011),
    • (2011) LNCS , vol.6632 , pp. 386-405
    • Shelat, A.1    Shen, C.-H.2
  • 65
    • 85028761718 scopus 로고
    • A Simple and Secure Way to Show the Validity of Your Public Key
    • Pomerance, C. (ed.) CRYPTO 1987. Springer, Heidelberg
    • van de Graaf, J., Peralta, R.: A Simple and Secure Way to Show the Validity of Your Public Key. In: Pomerance, C. (ed.) CRYPTO 1987. LNCS, vol. 293, pp. 128-134. Springer, Heidelberg (1988)
    • (1988) LNCS , vol.293 , pp. 128-134
    • Van De Graaf, J.1    Peralta, R.2
  • 66
    • 38049107739 scopus 로고    scopus 로고
    • Revisiting the Efficiency of Malicious Two-Party Computation
    • Naor, M. (ed.) EUROCRYPT 2007. Springer, Heidelberg
    • Woodruff, D.P.: Revisiting the Efficiency of Malicious Two-Party Computation. In: Naor, M. (ed.) EUROCRYPT 2007. LNCS, vol. 4515, pp. 79-96. Springer, Heidelberg (2007),
    • (2007) LNCS , vol.4515 , pp. 79-96
    • Woodruff, D.P.1
  • 68
    • 0020312165 scopus 로고
    • Protocols for secure computations
    • IEEE Computer Society
    • Yao, A.C.: Protocols for secure computations. In: Proc. FOCS 1982, pp. 160-164. IEEE Computer Society (1982)
    • (1982) Proc. FOCS 1982 , pp. 160-164
    • Yao, A.C.1
  • 69
    • 0022882770 scopus 로고
    • How to generate and exchange secrets
    • Yao, A.C.-C: How to generate and exchange secrets. In: FOCS 1986, pp. 162-167 (1986)
    • (1986) FOCS 1986 , pp. 162-167
    • Yao, A.C.-C.1


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.