All-or-Nothing Transforms as a countermeasure to differential side-channel analysis

Something About All or Nothing (Transforms)

In this short note, we study all-or-nothing transforms, which were recently proposed by Rivest as a mode of operation for block ciphers. We study transforms of this type that provide unconditional security. A simple construction for linear transforms is given, and some existence and non-existence results for general transforms are derived from a combinatorial characterization of these objects.

Wire-Tap Codes as Side-Channel Countermeasure

In order to provide security against side-channel attacks a masking scheme which makes use of wire-tap codes has recently been proposed. The scheme benefits from the features of binary linear codes, and its application to AES has been presented in the seminal article. In this work – with respect to the underlying scheme – we re-iterate the fundamental operations of the AES cipher in a hopefully...

Exposure-Resilient Fun tions and All-Or-Nothing Transforms

Exposure-Resilient Functions and All-or-Nothing Transforms

We study the problem of partial key exposure. Standard cryptographic definitions and constructions do not guarantee any security even if a tiny fraction of the secret key is compromised. We show how to build cryptographic primitives that remain secure even when an adversary is able to learn almost all of the secret key. The key to our approach is a new primitive of independent interest, which w...

On All - or - Nothing Transforms and Password - AuthenticatedKey

This thesis provides a formal analysis of two kinds of cryptographic objects that used to be treated with much less rigor: All-or-Nothing Transforms (AONTs) and Password-Authenticated Key Exchange protocols. For both, novel formal deenitions of security are given, and then practical and eecient constructions are proven secure. The constructions for password-authenticated key exchange are novel,...