Open AccessOleF: an Inverse-Free Online Cipher. An Online SPRP with an Optimal Inverse-Free Construction
Author(s) -
Ritam Bhaumik,
Mridul Nandi
Publication year - 2017
Publication title -
iacr transaction on symmetric cryptology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.715
H-Index - 10
ISSN - 2519-173X
DOI - 10.46586/tosc.v2016.i2.30-51
Subject(s) - computer science , block cipher , adversary , inverse , cipher , key (lock) , theoretical computer science , block (permutation group theory) , algorithm , cryptography , computer security , mathematics , encryption , combinatorics , geometry
Online ciphers, in spite of being insecure against an sprp adversary, can be desirable at places because of their ease of implementation and speed. Here we propose a single-keyed inverse-free construction that achieves online sprp security with an optimal number of blockcipher calls. We also include a partial block construction, without requiring any extra key.