A Parallel and Scalable Authenticated Encryption Algorithm
and Third Round Candidate in CAESAR



NORX is not patented and freely available for all applications. Its source code is available under the CC0 licence.

Old Specifications


Date Author(s) Language Link
2017-06-11 Philippe Leblanc Lua plc
2016-05-23 Tim Taubert (@ttaubert) Cryptol norx-cryptol
2016-05-11 James Humphry Ada/Spark spark_norx
2015-06-01 Joseph Birr-Pixton (@jpixton) C cifra
2015-03-13 Leon Botros C/AVR-Assembly norxavr
2015-01-05 Olan ÖK (@olanoek) Dart norx-dart
2015-01-05 Nadim Kobeissi (@kaepora) JavaScript norx.js
2014-12-04 Philipp Jovanovic (@Daeinar) Python2 norx-py
2014-07-07 Samuel Neves (@sevenps) Rust norx-rust
2014-05-29 Philipp Jovanovic (@Daeinar) Go norx-go
2014-03-27 Sebastian Gesemann (@EsGeh) C++ norxx
2014-03-19 Michael Samuel (@mik235) Python/Numpy norxpy

Projects Using NORX

Date Project
Jan. 2015 DEDIS Advanced Crypto Library for Go


Date Author(s) Publication
Nov. 2017 Serge Vaudenay,
Damian Vizar
Under Pressure: Security of Caesar Candidates beyond their Guarantees
IACR ePrint archive report 2017/1147
Nov. 2017 Luan Cardoso dos Santos,
Julio López
Pipeline Oriented Implementation of NORX for ARM Processors
SBSeg 2017
May 2017 Joan Daemen,
Bart Mennink,
Gilles Van Assche
Full-State Keyed Duplex With Built-In Multi-User Support
Asiacrypt 2017
Mar. 2017 Colin Chaigneau,
Thomas Fuhr,
Henri Gilbert,
Jérémy Jean,
Jean-René Reinhard
Cryptanalysis of NORX 2.0
Fast Software Encryption 2017
Jan. 2017 Alex Biryukov,
Aleksei Udovenko,
Vesselin Velichkov
Analysis of the NORX Core Permutation
IACR ePrint archive report 2017/034
Dec. 2016 Wen Cheng,
Jie Guan
On Linear Properties of G Function in NORX
Journal of Cryptologic Research
Nov. 2016 Ashutosh Dhar Dwivedi,
Milos Kloucek,
Pawel Morawiecki,
Ivica Nikolic,
Josef Pieprzyk,
Sebastian Wojtowicz
SAT-based Cryptanalysis of Authenticated Ciphers from the CAESAR Competition
IACR ePrint archive report 2016/1053
Mar. 2016 Nasour Bagheri,
Tao Huang,
Keting Jia,
Florian Mendel,
Yu Sasaki
Cryptanalysis of Reduced NORX
Fast Software Encryption 2016
IACR ePrint archive report 2016/436
Mar. 2015 Jean-Philippe Aumasson,
Philipp Jovanovic,
Samuel Neves
NORX8 and NORX16: Authenticated Encryption for Low-End Systems
TRUDEVICE workshop 2015
IACR ePrint archive report 2015/1154
Mar. 2015 Sourav Das,
Subhamoy Maitra,
Willi Meier
Higher Order Differential Analysis of NORX
IACR ePrint archive report 2015/186
Dec. 2014 Philipp Jovanovic,
Atul Luykx,
Bart Mennink
Beyond 2^{c/2} Security in Sponge-Based Authenticated Encryption Modes
IACR ePrint archive report 2014/373
Sept. 2014 Jean-Philippe Aumasson,
Philipp Jovanovic,
Samuel Neves
Analysis of NORX: Investigating Differential and Rotational Properties
Latincrypt 2014
IACR ePrint archive report 2014/317
Sept. 2014 Jean-Philippe Aumasson,
Philipp Jovanovic,
Samuel Neves
NORX: Parallel and Scalable AEAD


Date Author(s) Resource
Jun. 2015 Joseph Birr-Pixton Benchmarking Modern Authenticated Encryption on 1€ Devices.
NORX among fastest ciphers on small processors. Benchmarked using cifra platform.


High Security

NORX supports secret key and authentication tag sizes of 128- and 256-bits, respectively.


NORX was designed for 32- and 64-bit CPUs, but also with hardware friendliness in mind.


Tunable parallelism, SIMD and hardware friendliness enable high speeds across platforms.


Clean design principles allow a straightforward implementation of the NORX cipher.


Different tunable parameters make NORX highly adaptable to various use cases.

Simple Integration

Flexible datagram processing enables an easy integration into arbitrary protocol stacks.

Minimal Overhead

The length of the ciphertext is the sum of the lengths of plaintext and authentication tag.


Datagrams encode parameters of NORX and encapsulate protected data to improve interoperability.

Side-Channel Robustness

Well-considered components facilitate the hardening of NORX against timing attacks.


Should you have any questions or feedback, please do not hesitate to contact us. The e-mail address below forwards to the three designers. If 140 characters are sufficient, you can find us also on twitter.