On Hiding a Plaintext Length by Preencryption

It is a well known fact that encryption schemes can not hide a plaintext length when it is unbounded. We thus admit that an approximation of it may leak and we focus on hiding its precise value. Some standards such as TLS or SSH offer to do it by applying some pad-then-encrypt techniques. In this study, we investigate the information leakage when these techniques are used. We define the notion of padding scheme and its associated security. We show that when a padding length is uniformly distributed, the scheme is nearly optimal. We also show that the insecurity degrades linearly with the padding length.


Published in:
Proceedings of ACNS'11
Presented at:
ACNS, Malaga, Spain, June 7-10, 2011
Year:
2011
Publisher:
Springer
Laboratories:




 Record created 2011-06-08, last modified 2018-03-17

n/a:
Download fulltext
PDF

Rate this document:

Rate this document:
1
2
3
 
(Not yet reviewed)