Publications by Reza Reyhanitabar

Power Yoga: Variable-Stretch Security of CCM for Energy-Efficient Lightweight IoT

Damian Vizár, Reza Reyhanitabar, Emiljano Gjiriti

The currently ongoing NIST LWC project aims at identifying new standardization targets for lightweight authenticated encryption with associated data (AEAD) and (optionally) lightweight cryptographic hashing. NIST has deemed it important for performance and ...

2021

Authenticated Encryption with Variable Stretch

Serge Vaudenay, Damian Vizár, Reza Reyhanitabar

In conventional authenticated-encryption (AE) schemes, the ciphertext expansion, a.k.a.stretch or tag length, is a constant or a parameter of the scheme that must be fixed per key. However, using variable-length tags per key can be desirable in practice or ...

Springer-Verlag Berlin2016

Online Authenticated-Encryption and its Nonce-Reuse Misuse-Resistance

Damian Vizár, Reza Reyhanitabar

A definition of online authenticated-encryption (OAE), call it OAE1, was given by Fleischmann, Forler, and Lucks (2012). It has become a popular definitional target because, despite allowing encryption to be online, security is supposed to be maintained ev ...

Springer2015

Boosting OMD for Almost Free Authentication of Associated Data

Serge Vaudenay, Damian Vizár, Reza Reyhanitabar

We propose pure OMD (p-OMD) as a new variant of the Offset Merkle-Damgård (OMD) authenticated encryption scheme. Our new scheme inherits all desirable security features of OMD while having a more compact structure and providing higher efficiency. The origi ...

Springer2015

Security of Full-State Keyed Sponge and Duplex: Applications to Authenticated Encryption

Damian Vizár, Reza Reyhanitabar

We provide a security analysis for full-state keyed Sponge and full-state Duplex constructions. Our results can be used for making a large class of Sponge-based authenticated encryption schemes more efficient by concurrent absorption of associated data and ...

Springer2015

OMD: A Compression Function Mode of Operation for Authenticated Encryption

Serge Vaudenay, Damian Vizár, Reza Reyhanitabar

We propose the Offset Merkle-Damgård (OMD) scheme, a mode of operation to use a compression function for building a nonce-based authenticated encryption with associated data. In OMD, the parts responsible for privacy and authenticity are tightly coupled to ...

Springer International Publishing2014

Misuse-Resistant Variants of the OMD Authenticated Encryption Mode

Serge Vaudenay, Damian Vizár, Reza Reyhanitabar

We present two variants of OMD which are robust against nonce misuse. Security of OMD---a CAESAR candidate---relies on the assumption that implementations always ensure correct use of nonce (a.k.a. message number); namely that, the nonce never gets repeate ...

Springer-Verlag Berlin2014