The rapid adaptation to mobile devices and data sharing has changed our life style significantly. Despite the fact that this provides extraordinary comfort and proficiency, it also imposes greater challenges in ensuring a secure transfer of sensitive information through these devices. This information could be highly confidential that the owner wants to provide access privileges only to authorized individuals. Many cryptographic algorithms together with potent data protection mechanisms available today are robust enough to ensure the Confidentiality, Integrity and Availability of information. One significant use-case in this regard that this research work tries to address is when the data owner only wants to share the data securely with the authorized user, making it extremely difficult for the user to store or make a copy of the data or to share it with others.
A detailed literature survey is presented, that discusses the previous research addressing the security issues in sharing the data with third party cloud servers to distribute the data to authorized end-users. Enhancements in the field of security to protect the data in third party Cloud service providers and also to protect data in user’s devices appear to be increasingly significant to ensure data privacy and protection in an efficient and feasible way.
This thesis is focused to design a sharing system where owners can share the data with authorized users through third party cloud service providers. The CSPs will not be able to read the underlying plain text and the overhead of storing files has been significantly reduced compared to traditional asymmetric systems as only a single file encrypted with owner’s public key along with the different re-encryption keys is stored in the CSP for multiple users. Together with the file sharing mechanism, a significant and distinct scenario that this thesis work greatly focused on is
to ensure security when the data owner only wants to share the data securely with the authorized user, and making it extremely difficult for the user to store or make a copy of the data or to share it with others. In this scenario, it is practically impossible for the data owner to be available and spy on the user all the time to ensure these security requirements are met. Security in the user’s device has been achieved with a novel way of leveraging the security features of recipient’s device, mobile device (iOS) in this case. This work is possible on a non-jailbroken IOS device which acts as a recipient’s device, as it prevents the users and attackers to override the security features of the mobile device as described in chapter 4 to attack the application and read the data from memory at runtime.
This work would be very valuable when one wants to share the files through a third party cloud service provider and restrict the end users to store or share the data with other unauthorized users. This mechanism can be handy in the applications such as snapchat, where the pictures of the users are not supposed to be stored in the device. Though there is a possibility of users taking the picture of the data with another camera still they cannot be able to obtain the same metadata of the original file.
The security of the proposed protocol in this thesis work has been verified by using Scyther automated security protocol verification tool. The experimental evaluation and results show that the proposed scheme only contributes to a negligible computational and storage overhead at the proxy server and at the data owner and data user, it doesn’t add any significant overhead in terms of computation, storage and communication. This proves that the proposed scheme is practical without adding overhead to the original proxy re-encryption algorithm and can be effectively used to share sensitive data with authorized users while preventing the users from sharing with unauthorized users.
Future Work
This work has a wide scope and it opens an avenue for further research in enhancing the security at the end-user’s device. In this research, it is assumed that the end-user’s device is a non- jailbroken IOS device for making sure the security features provided by the IOS operating system are intact and not tampered. The security features such as sandbox and ASLR provided by mobile operating systems are crucial in making sure that the memory being used by the application is not attacked or read by other applications. There is extreme research being done in hardening the mobile devices to prevent the jail breaks, this by itself opens up a different area of research.
This thesis focused primarily only on the data sharing system and protecting the data at end-user’s device but as of now, it doesn’t yet provide the facility to revoke access to the files by the end-users. If the end-user, for some reason revokes the current public-private key pair he is using, there is no way he can receive the blocks of data because the old re-encryption key would now be no longer valid. Again a secure hand-shake mechanism should take place between the data owner and the end-user to authenticate the user and verify the new key-pair. Also, CSP is assumed to be semi-trusted in this scheme because the number of times a user can access the data is decided by the owner and implemented by the CSP. As of now, the data owner doesn’t verify if the CSP is providing access more number of times. Also, access to the end-users is provided by the help of CSP, so we have to make sure that the CSP will not provide access to the data after the owner informs it to revoke access to a particular user.
Another possibility of enhancing this research is to include identity based cryptographic techniques into this system and then sharing data based on the user access privileges. This can be achieved by adding a unique personal information related to user such as location or IPaddress to generate a public key.
REFERENCES
[1] Cherdantseva Y. and Hilton J.: "Information Security and Information Assurance. The Discussion about the Meaning, Scope and Goals". In: Organizational, Legal, and Technological Dimensions of Information System Administrator. Almeida F., Portela, I. (eds.). IGI Global Publishing. (2013)
[2] B., McDermott, E., & Geer, D. (2001). Information security is information risk management. In Proceedings of the 2001 Workshop on New Security Paradigms NSPW ‘01, (pp. 97 – 104). ACM. doi:10.1145/508171.508187
[3] Peltier, Thomas R. (2001). Information Security Risk Analysis. Boca Raton, FL: Auerbach publications. [4] https://cloudsecurityalliance.org/topthreats/csathreats.v1.0.pdf
[5] E. Goh, H. Shacham, N. Modadugu, and D. Boneh, “SiRiUS: Securing remote untrusted storage,” in Proceedings of the Tenth Network and Distributed System Security (NDSS) Symposium. Citeseer, 2003, pp. 131–145.
[6] R. Anderson: Security Engineering: a guide to building dependable distributed systems John Wiley & Sons (2010), p. 640
[7] Ferraiolo DF and Kuhun DR. 1992. Role Based Access Control. Proceeding of 15th National Computer Security Conference, Baltimore MD. pp. 554-563.
[8] R. Ausanka-Crues Methods for access control: advances and limitations Harvey Mudd College (2004) Retrieved December 07, 2012
[9] S. Harris Mike Meyers' CISSP(R) Certification Passport (1st ed.)McGraw-Hill, United States (2002), p.422 [10] B.W. Lampson Protection Fifth Princeton Symposium on Information Sciences and Systems, Princeton University, Princeton, NJ (1974), pp. 18–24
[11] P. Samarati, S. de Vimercati Access control: policies, models, and mechanisms Foundations of Security Analysis and Design (2001)
[12] C. Ardagna, M. Cremonini, E. Damiani, S. di Vimercati, and P. Samarati, “Supporting location-based conditions in access control policies,” in Proceedings of the 2006 ACM Symposium on Information, computer and communications security. ACM, 2006, p. 222.
[13] V. Hu, D. Ferraiolo, and D. Kuhn, “Assessment of access control systems,” Interagency Report, vol. 7316, pp. 20 899–8930, 2006
[14] R. Canetti and S. Hohenberger. Chosen-ciphertext secure proxy re-encryption. Proceedings of the 14th ACM conference on Computer and communications security CCS 2007, pages 185 194. ACM, 2007.
[15] M. Georgiev, S. Iyengar, S. Jana, R. Anubhai, D. Boneh, and V. Shmatikov. The most dangerous code in the world: Validating SSL certificates in non-browser software. In T. Yu, G. Danezis, and V. D. Gligor, editors, ACM Conference on Computer and Communications Security, pages 38–49. ACM, 2012.
[16] J. Daemen and V. Rijmen. The Design of Rijndael: AES - The Advanced Encryption Standard. Springer, 2002.
[17] Institute of Electrical and Electronics Engineers (IEEE), Standard Specifications For Public-Key Cryptography. IEEE P1363, 2000.
[18] W. Diffie and M. E. Hellman. New directions in cryptography. IEEE Transactions on Information Theory, 22(6):644–654, 197
[19] R. L. Rivest, A. Shamir and L. Adleman “A method for obtaining digital signatures and public-key cryptosystems” Communications of the ACM, vol. 21, pp. 120-126, 1978.
[20] Friederike Brezing and Annegret Weng, Elliptic curves suitable for pairing based cryptography, Des. Codes Cryptography 37 (2005), no. 1, 133–141.
[21] T. ElGamal "A public-key cryptosystem and a signature scheme based on discrete logarithms" IEEE Trans. on Information Theory vol. 31 pp. 469-472 1985.
[22] G.Ateniese, K. Fu, M. Green, S. Hohenberger, Improved Proxy Re- encryption Schemes with Applications to Secure Distributed Storage. ACM Trans. Inf. Syst. Secur. 9-1-30 , 2006.
[23] J.Bethencourt, “Intro to Bilinear Maps”, http://people.csail.mit.edu/alinush/6.857-spring- 2015/papers/bilinear-maps.pdf
[24] S. Yilek, E. Rescorla, H. Shacham, B. Enright, and S. Savage. When private keys are public: results from the 2008 Debian OpenSSL vulnerability. In A. Feldmann and L. Mathy, editors, Internet Measurement Conference, pages 15–27. ACM, 2009.
[25] QingLi, Clark,G, "Mobile Security: A Look Ahead, "Security& Privacy, IEEE , vol.11, no.1, pp.78,81, Jan.- Feb. 2013
[26] Rosilah Hassan, Muhammad Syahrin Ab. Rahman, Mohd Rosmadi Mokhtar, Aini Aman, Mobile Accounting Version 1 Design of Mobile Costing Application for MSMEs Using Android, IEEE ICACT 2013, PyongChang Korea Jan 27-30, 2013, pp.697-701.
[27] Tae Oh; Stackpole, B.; Cummins, E.; Gonzalez, C.; Ramachandran, R.; Shinyoung Lim, "Best security practices for android, blackberry, and iOS," Enabling Technologies for Smartphone and Internet of Things (ETSIoT), 2012 First IEEE Workshop on , vol., no., pp.42,47, 18-18 June 2012
[28] http://www.apple.com/ipad/business/it-center/deployment-mdm.html
[29] X. Liang, Z.Cao, H. Lin, and J. Shao. Attribute based proxy re- encryption with delegating capabilities, ASIACCS, pages 276-286. ACM, 2009.
[30] Ma Mambo and E. Okamoto. Proxy cryptosystems: Delegation of the power to decrypt ciphertexts. IEICE Transactions, E8O-A(1):54-63, 1997.
[31] M. Blaze, G. Bleumer, and M. Strauss. Divertible protocols and atomic proxy cryptography. Advances in Cryptology - EUROCRYPT 1998, volume 1403 of LNCS, pages 127 144. Springer-Verlag, 1998.
[32] Son J, Kim D, Hussain R Conditional proxy re-encryption for secure big data group sharing in cloud environment. In Proceedings of 2014 I.E. Conference on Computer Communications Workshops. Toronto, Canada, pp 541–546
[33] A. Sahai and B. Waters. Fuzzy identity-based encryption, Advances in Cryptology EUROCRYPT 2005, volume 3494 of LNCS, pages 457 473. Springer - Verlag, 2005.
[34] D. Boneh and M. Franklin. Identity-based encryption from the weil pairing, Advance in Cryptology CRYPTO 2001, volume 2139 of LNCS, pages 213 -229. Springer-Verlag, 2001.
[35] V. Goyal, O. Pandey, A. Sahai, and B. Waters. Attribute-based encryption for fine-grained access control of encrypted data. Proceedings of the 13th ACM conference on Computer and communications security {CCS 2006}, pages 89 98. ACM, 2006.
[36] J. Bethencourt, A. Sahai, and B. Waters. Ciphertext-policy attribute-based encryption. In IEEE Symposium on Security and Privacy, S&P 2007, pages 321334. IEEE Computer Society, 2007.
[37] V Bozovic, D Socek, R Steinwandt, and V. I. Villanyi, Multi-authority attribute-based encryption with honest-but-curious central authority," International Journal of Computer Mathematics, vol. 89,pp. 3, 2012. [38] S. Muller, S. Katzenbeisser, and C. Eckert. Distributed attribute-based encryption, Information Security and Cryptology ICISC 2008, volume 5461 of LNCS, pages 20 36. Springer - Verlag, 2008.
[39] P. K. Tysowski, M. A. Hasan: Hybrid Attribute- and Re-Encryption- Based Key Management for Secure and Scalable Mobile Applications in Clouds. IEEE T. Cloud Computing 1(2): 172-186 (2013)
[40] Y. Kawai, Outsourcing the Re-encryption Key Generation: Flexible Ciphertext-Policy Attribute-Based Proxy Re-Encryption, International Conference on Information Security Practice and Experience (ISPEC 2015), Beijing, China, May 2015.
[41] J. Lai,, R. H. Deng, Y. Yang, and J. Weng, Adaptable Ciphertext-Policy Attribute-Based Encryption, InParing 2013. LNCS, vol.8365, pp.199-214. Springer, Heidelberg, 2014.
[42] S. Fugkeaw and H. Sato, Embedding Lightweight Proxy Re-Encryption for Efficient Attribute Revocation in Cloud Computing, International Journal on High Performance Computing and Networking, (In press) 2016. [43] C. K. Chu and W. G. Tzeng. Identity-based proxy re-encryption without random oracles. In J. Garay, A. K. Lenstra, M. Mambo, and R. Peralta, editors, Information Security ISC 2007, volume 4779, pages 189 202. Springer - Verlag, 2007.
[44] M. Blaze. A cryptographic file system for unix. In Proceedings of the 1st ACM conference on Computer and communications security CCS 1993, pages 9 16. ACM, 1993.
[45] M. Kallahalla, E. Riedel, R. Swaminathan, Q. Wang, and K. Fu, “Plutus: Scalable secure file sharing on untrusted storage,” in Proceedings of the 2nd USENIX Conference on File and Storage Technologies. Berkeley, CA, USA: USENIX Association, 2003, pp. 29–42.
[46] D. Naor, M. Naor, and J. Lotspiech, “Revocation and tracing schemes for stateless receivers,” in Advances in Cryptology–CRYPTO 2001. Springer, 2001, pp. 41–62.
[47] D. Li, X. Du, X. Hu, L. Ruan, and X. Jia, “Minimizing number of wavelengths in multicast routing trees in wdm networks,” Networks, vol. 35, no. 4, pp. 260–265, 2000.
[48] S. Di Vimercati, S. Foresti, S. Jajodia, S. Paraboschi, and P. Samarati, “Over-encryption: management of access control evolution on outsourced data,” in Proceedings of the 33rd international conference on Very large data bases. VLDB Endowment, 2007, pp. 123–134.
[49] S. D. C. di Vimercati, S. Foresti, S. Jajodia, S. Paraboschi, and P. Samarati, “A data outsourcing architecture combining cryptography and access control,” in Proceedings of the 2007 ACM workshop on Computer security architecture, ser. CSAW ’07. New York, NY, USA:
ACM, 2007, pp. 63–69.
[50] W. Wang, Z. Li, R. Owens, and B. Bhargava, “Secure and efficient access to outsourced data,” in Proceedings of the 2009 ACM workshop on Cloud computing security. ACM, 2009, pp. 55–66.
[51] A. Fiat and M. Naor. Broadcast encryption. Advances in Cryptology CRYPTO 1993, volume 773 of LNCS, pages 480 491. Springer - Verlag, 1993.
[52] D. Boneh, C. Gentry, and B. Waters. Collusion resistant broadcast encryption with short ciphertexts and private keys, Advances in Cryptology CRYPTO 2005, volume 3621 of LNCS, pages 258 275. Springer - Verlag, 2005.
[53] Basin, D., & Cremers, C. (2010). Modeling and analyzing security in the presence of compromising adversaries. In Computer Security-ESORICS 2010(pp. 340- 356). Berlin Heidelberg: Springer
[54] http://gas.dia.unisa.it/projects/jpbc/#.WI2-JrYrK1s [55] https://crypto.stanford.edu/pbc/