A Concept for Securing Cyber-Physical Systems with Organic Computing Techniques. - Jörg Hähner; Stefan Rudolph; Sven Tomforde; Dominik Fisch; Bernhard Sick; Nils Kopal; Arno Wacker (ARCS Workshops, 2013)

Ranking Cryptographic Algorithms. - Olga Kieselmann; Nils Kopal; Arno Wacker (Socio-technical Design of Ubiquitous Computing Systems, 2014)

Solving the Double Transposition Challenge with a Divide-and-Conquer Approach. - George Lasry; Nils Kopal; Arno Wacker (Cryptologia, 2014)

CrypTool 2.0. - Nils Kopal; Olga Kieselmann; Arno Wacker; Bernhard Esslinger (Datenschutz und Datensicherheit, 2014)

Analysis and monitoring of hidden TCP traffic based on an open-source covert timing channel. - Angelo Liguori; Francesco Benedetto; Gaetano Giunta; Nils Kopal; Arno Wacker (CNS, 2015)

A Novel Approach to Data Revocation on the Internet. - Olga Kieselmann; Nils Kopal; Arno Wacker (DPM/QASA@ESORICS, 2015)

Simulating Cheated Results Dissemination for Volunteer Computing. - Nils Kopal; Olga Kieselmann; Arno Wacker (FiCloud, 2015)

SoftGap: A Multi Independent Levels of Security Cross-Domain Solution. - Angelo Liguori; Francesco Benedetto; Gaetano Giunta; Nils Kopal; Arno Wacker (FiCloud, 2015)

"Löschen" im Internet. - Olga Kieselmann; Nils Kopal; Arno Wacker (Datenschutz und Datensicherheit, 2015)

Volume Raycasting mit OpenCL. - Nils Kopal (CoRR, 2016)

Rational Unified Process. - Nils Kopal (CoRR, 2016)

Automated Known-Plaintext Cryptanalysis of Short Hagelin M-209 Messages. - George Lasry; Nils Kopal; Arno Wacker (Cryptologia, 2016)

Ciphertext-only cryptanalysis of Hagelin M-209 pins and lugs. - George Lasry; Nils Kopal; Arno Wacker (Cryptologia, 2016)

Cryptanalysis of columnar transposition cipher with long keys. - George Lasry; Nils Kopal; Arno Wacker (Cryptologia, 2016)

Cryptanalysis of Chaocipher and solution of Exhibit 6. - George Lasry; Moshe Rubin; Nils Kopal; Arno Wacker (Cryptologia, 2016)

Adaptive Cheat Detection in Decentralized Volunteer Computing with Untrusted Nodes. - Nils Kopal; Matthäus Wander; Christopher Konze; Henner Heck (DAIS, 2017)

Deciphering ADFGVX messages from the Eastern Front of World War I. - George Lasry; Ingo Niebel; Nils Kopal; Arno Wacker (Cryptologia, 2017)

A Decentralized Resilient Short-Term Cache for Messaging. - Henner Heck; Olga Kieselmann; Nils Kopal; Arno Wacker (DAIS, 2018)

Solving Classical Ciphers with CrypTool 2. - Nils Kopal (HistoCrypt, 2018)

Ciphertext-only cryptanalysis of short Hagelin M-209 ciphertexts. - George Lasry; Nils Kopal; Arno Wacker (Cryptologia, 2018)

Secure Volunteer Computing for Distributed Cryptanalysis. - Nils Kopal (2018)

Cryptanalysis of Homophonic Substitution Ciphers Using Simulated Annealing with Fixed Temperature. - Nils Kopal (HistoCrypt, 2019)

Cryptanalysis of Enigma double indicators with hill climbing. - George Lasry; Nils Kopal; Arno Wacker (Cryptologia, 2019)

Of Ciphers and Neurons - Detecting the Type of Ciphers Using Artificial Neural Networks. - Nils Kopal (HistoCrypt, 2020)

Decryption of historical manuscripts: the DECRYPT project. - Beáta Megyesi; Bernhard Esslinger; Alicia Fornés; Nils Kopal; Benedek Láng; George Lasry; Karl de Leeuw; Eva Pettersson; Arno Wacker; Michelle Waldispühl (Cryptologia, 2020)

Detection of Classical Cipher Types with Feature-Learning Approaches. - Ernst Leierzopf; Vasily Mikhalev; Nils Kopal; Bernhard Esslinger; Harald Lampesberger; Eckehard Hermann (AusDM, 2021)

Island Ramanacoil a Bridge too Far. A Dutch Ciphertext from 1674. - Jörgen Dinnissen; Nils Kopal (HistoCrypt, 2021)

Two Encrypted Diplomatic Letters Sent by Jan Chodkiewicz to Emperor Maximilian II in 1574-1575. - Nils Kopal; Michelle Waldispühl (HistoCrypt, 2021)

A Massive Machine-Learning Approach For Classical Cipher Type Detection Using Feature Engineering. - Ernst Leierzopf; Nils Kopal; Bernhard Esslinger; Harald Lampesberger; Eckehard Hermann (HistoCrypt, 2021)

Deciphering papal ciphers from the 16th to the 18th Century. - George Lasry; Beáta Megyesi; Nils Kopal (Cryptologia, 2021)

Evaluating Deep Learning Techniques for Known-Plaintext Attacks on the Complete Columnar Transposition Cipher. - Nino Fürthauer; Vasily Mikhalev; Nils Kopal; Bernhard Esslinger; Harald Lampesberger; Eckehard Hermann (HistoCrypt, 2022)

New Ciphers and Cryptanalysis Components in CrypTool 2. - Nils Kopal; Bernhard Esslinger (HistoCrypt, 2022)

What Was Encoded in Historical Cipher Keys in the Early Modern Era? - Beáta Megyesi; Crina Tudor; Benedek Láng; Anna Lehofer; Nils Kopal; Michelle Waldispühl (HistoCrypt, 2022)

How we set new world records in breaking Playfair ciphertexts. - Elonka Dunin; Magnus Ekhall; Konstantin Hamidullin; Nils Kopal; George Lasry; Klaus Schmeh (Cryptologia, 2022)

Deciphering three diplomatic letters sent by Maximilian II in 1575. - Nils Kopal; Michelle Waldispühl (Cryptologia, 2022)

Historical Language Models in Cryptanalysis: Case Studies on English and German. - Beáta Megyesi; Justyna Sikora; Filip Fornmark; Michelle Waldispühl; Nils Kopal; Vasily Mikhalev (HistoCrypt, 2023)

What is the Code for the Code? Historical Cryptology Terminology. - Vasily Mikhalev; Nils Kopal; Bernhard Esslinger; Michelle Waldispühl; Benedek Láng; Beáta Megyesi (HistoCrypt, 2023)

ICDAR 2024 Competition on Handwriting Recognition of Historical Ciphers. - Alicia Fornés; Jialuo Chen; Pau Torras; Carles Badal; Beáta Megyesi; Michelle Waldispühl; Nils Kopal; George Lasry (ICDAR (6), 2024)

Keys with nomenclatures in the early modern Europe. - Beáta Megyesi; Crina Tudor; Benedek Láng; Anna Lehofer; Nils Kopal; Karl de Leeuw; Michelle Waldispühl (Cryptologia, 2024)

Evaluating GPT-4's proficiency in addressing cryptography examinations. - Vasily Mikhalev; Nils Kopal; Bernhard Esslinger (Cryptologia, 2025)