- Cite this paper as:
- Liskov M., Micali S. (2008) Online-Untransferable Signatures. In: Cramer R. (eds) Public Key Cryptography – PKC 2008. PKC 2008. Lecture Notes in Computer Science, vol 4939. Springer, Berlin, Heidelberg
Non-transferability of digital signatures is an important security concern, traditionally achieved via interactive verification protocols. Such protocols, however, are vulnerable to “online transfer attacks” — i.e., attacks mounted during the protocols’ executions.
In this paper, we show how to guarantee online untransferability of signatures, via a reasonable public-key infrastructure and general assumptions, without random oracles. Our untransferable signatures are as efficient as prior ones that provably provide weaker types of untransferability.