Extended Sanitizable Signatures
Sanitizable signatures introduced by Ateniese et al. is a powerful and fairly practical tool that enables an authorised party called the censor to modify designated parts of a signed message in an arbitrary way without interacting with the signer. In our paper we present several extensions of this paradigm that make sanitizable signatures even more useful. First of all we show how to limit the censor’s abilities to modify mutable parts of a signed message to a predetermined set of strings. In our next proposal we show how to construct a scheme wherein the censor can insert an arbitrary string into a document, but this must be the same string in all designated places. We also present a construction based on a sanitizable signature that allows the censor to present only a constant number of versions of the sanitized message. Another extension provides so-called strong transparency. In this case the verifier does not know which parts of the message could have been modified. Finally, we point out new applications of sanitizable signatures based on combining them with time released cryptography techniques.
KeywordsHash Function Signature Scheme Bloom Filter Signed Message Accumulator Technique
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- 3.Benaloh, J., de Mare, M.: One-Way Accumulators: A Decentralised Alternative to Digital Signatures. In: Helleseth, T. (ed.) EUROCRYPT 1993. LNCS, vol. 765, pp. 274–285. Springer, Heidelberg (1994)Google Scholar
- 9.Klonowski, M., Kutyłowski, M., Lauks, A., Zagórski, F.: Conditional Digital Signatures. In: Katsikas, S.K., López, J., Pernul, G. (eds.) TrustBus 2005. LNCS, vol. 3592, pp. 490–497. Springer, Heidelberg (2005)Google Scholar
- 10.Krawczyk, H., Rabin, T.: Chameleon Signatures. In: Proceedings of the Network and Distributed System Security Symposium NDSS 2000, pp. 143–154 (2000)Google Scholar
- 11.May, T.C.: Time-release crypto (February 1993), http://www.hks.net/cpunks/cpunks0/1460.html
- 13.Miyazaki, K., Hanaoka, G., Imai, H.: Digitally Signed Document Sanitizing Scheme Based on Bilinear Maps. In: ACM Symposium on InformAtion, Computer and Communications Security (ASIACCS 2006), Taipei, Taiwan, March 21-24 (2006)Google Scholar
- 14.Miyazaki, K., Iwamura, M., Matsumoto, T., Sasaki, R., Yoshiura, H., Tezuka, S., Imai, H.: Digitally Signed Document Sanitizing Scheme with Disclosure Condition Control. The Institute of Electronics, Information and Communication Engineers (IEICE) Trans. on Fundamentals E88-A(1), 239–246 (2005)Google Scholar
- 15.Rivest, R.L.: Two Signatures Schemes, Slides from talk given at Cambridge University, October 17 (2000), http://theory.lcs.mit.edu/~rivest/publications.html
- 16.Rivest, R.L., Shamir, A., Wagner, D.A.: Time-lock puzzles and timed-released Crypto, Revisited version, March 10 (1996), http://theory.lcs.mit.edu/~rivest/publications.html