Memory Erasability Amplification
Erasable memory is an important resource for designing practical cryptographic protocols that are secure against adaptive attacks. Many practical memory devices such as solid state drives, hard disks, or file systems are not perfectly erasable because a deletion operation leaves traces of the deleted data in the system. A number of methods for constructing a large erasable memory from a small one, e.g., using encryption, have been proposed. Despite the importance of erasable memory in cryptography, no formal model has been proposed that allows one to formally analyse such memory constructions or cryptographic protocols relying on erasable memory.
The contribution of this paper is three-fold. First, we provide a formal model of erasable memory. A memory device allows a user to store, retrieve, and delete data, and it is characterised by a leakage function defining the extent to which erased data is still accessible to an adversary.
Second, we investigate how the erasability of such memories can be amplified. We provide a number of constructions of memories with strong erasability guarantees from memories with weaker guarantees. One of these constructions of perfectly erasable memories from imperfectly erasable ones can be considered as the prototypical application of Canetti et al.’s All-or-Nothing Transform (AoNT). Motivated by this construction, we propose some new and better AoNTs that are either perfectly or computationally secure. These AoNTs are of possible independent interest.
Third, we show (in the constructive cryptography framework) how the construction of erasable memory and its use in cryptographic protocols (for example to achieve adaptive security) can naturally be composed to obtain provable security of the overall protocol.
KeywordsSecure memory erasure Secure deletion Adaptive corruption Constructive cryptography All-or-nothing-transforms (AoNT)
- 1.Bernstein, D.J.: Cache-timing attacks on AES. Manuscript, April 2005. https://cr.yp.to/antiforgery/cachetiming-20050414.pdf
- 4.Canetti, R., Eiger, D., Goldwasser, S., Lim, D.-Y.: How to protect yourself without perfect shredding. In: Aceto, L., Damgård, I., Goldberg, L.A., Halldórsson, M.M., Ingólfsdóttir, A., Walukiewicz, I. (eds.) ICALP 2008, Part II. LNCS, vol. 5126, pp. 511–523. Springer, Heidelberg (2008)CrossRefGoogle Scholar
- 5.Canetti, R., Eiger, D., Goldwasser, S., Lim, D.-Y.: How to protect yourself without perfect shredding. Cryptology ePrint Archive, Report 2008/291 (2008)Google Scholar
- 7.Franklin, M.K., Yung, M.: Communication complexity of secure computation (extended abstract). In: 24th ACM STOC, pp. 699–710. ACM Press, May 1992Google Scholar
- 8.Gaži, P., Maurer, U., Tackmann, B.: Manuscript. (available from the authors)Google Scholar
- 9.Gutmann, P.: Secure deletion of data from magnetic and solid-state memory. In: Proceedings of the Sixth USENIX Security Symposium, vol. 14, San Jose, CA (1996)Google Scholar
- 10.Hazay, C., Lindell, Y., Patra, A.: Adaptively secure computation with partial erasures. Cryptology ePrint Archive, Report 2015/450 (2015)Google Scholar
- 13.Lim, D.-Y.: The paradigm of partial erasures. Ph.D. thesis, Massachusetts Institute of Technology (2008)Google Scholar
- 15.Maurer, U., Renner, R.: Abstract cryptography. In: ICS 2011, pp. 1–21. Tsinghua University Press, January 2011Google Scholar
- 17.Reardon, J., Basin, D.A., Capkun, S.: SoK: secure data deletion. In: 2013 IEEE Symposium on Security and Privacy, pp. 301–315. IEEE Computer Society Press, May 2013Google Scholar
- 18.Reardon, J., Capkun, S., Basin, D.: Data node encrypted file system: efficient secure deletion for flashmemory. In: Proceedings of the 21st USENIX Conference on Security Symposium, pp. 17–17. USENIX Association (2012)Google Scholar
- 19.Reardon, J., Ritzdorf, H., Basin, D.A., Capkun, S.: Secure data deletion from persistent media. In: ACM CCS 2013, pp. 271–284. ACM Press, November 2013Google Scholar
- 20.Yee, B.: Using secure coprocessors. Ph.D. thesis, CMU (1994)Google Scholar
- 21.Yee, B., Tygar, J.D.: Secure coprocessors in electronic commerce applications. In: Proceedings of The First USENIX Workshop on Electronic Commerce, New York (1995)Google Scholar