Date Added: Sep 2012
Consider the following scenario: Alice encrypts her data today using the most trusted computationally secure cryptosystem. An adversary Eve gains access to the encrypted data and stores it in a safe place. Sensitive electronic data may be required to remain confidential for long periods of time. Yet encryption under a computationally secure cryptosystem cannot provide a guarantee of long term confidentiality, due to potential advances in computing power or cryptanalysis. Long term confidentiality is ensured by information theoretically secure ciphers, but at the expense of impractical key agreement and key management. The authors overview known methods to alleviate these problems, whilst retaining some form of information theoretic security relevant for long term confidentiality.