Security · Software

Threat Model Your World

Custom software and app development, world-class cybersecurity, and technical publications. Since 2006.

My Experience from 25 years of IT projects View Projects
0+ Years of Experience
0+ Published Apps
0 Technical Books
Scroll
What I do

My Experience

Cybersecurity

Penetration testing, reverse engineering, threat modeling, coaching and strategy. Experience with classified government projects up to top secret level.

PentestingReverse EngineeringComplianceSecure Development LifecycleEU Cyber Resilience Act

App Development

Native iOS and Android apps with a focus on security, performance, and intuitive design. From whitelabel solutions to custom high-security applications.

iOSAndroidHybrid

Software Development

Custom software solutions for complex requirements. Secure multi-layer architectures, cryptography frameworks, and infrastructure projects.

BackendCryptographyPKIE-Health

Publications

14 technical books on iOS development, networking, and server administration. Regular articles about security, programming, and AI.

BooksArticlesTalksTV
References

Selected Projects

A selection from over 25 years of successful project work.

2006 — present
Security

Cybersecurity

Long-term security advisory for SMEs and enterprises. Penetration testing, security audits, and strategic IT security guidance.

2021 — 2022
App

CovPass App

Advisory on the development of Germany's official CovPass app for digital COVID certificate management.

2021
Infrastructure

Certificate Authority Appliance

Implementation of a Certificate Authority appliance for a major enterprise client in the PKI domain.

2020
Software

Lottery System & E-Health

Development of a secure lottery system and infrastructure projects in the e-health sector.

2019 — 2020
Security

Secure Multi-Layer Architecture

Design and implementation of secure multi-layer architectures for banks and financial service providers.

2018
App

Health & Utilities App

Implementation of a health app and a municipal utilities app for the city of Düsseldorf.

2015
Software

Cryptography Framework

Development of a cryptography framework for an international airline.

2014 — 2019
App

Whitelabel Utilities Apps

Over 40 published whitelabel apps for municipal utility companies across Germany.

2008
Security

IT Infrastructure — Federal Agency

Setup of IT infrastructure for a German federal agency with top secret classification.

Sharing knowledge

Books & Publications

14 technical books, numerous articles, and media appearances.

2025

Rodewig: "Boosting Xcode and Swift: What's New for Developers at WWDC 2025" · Mac & i, Heise Verlag

2025

Rodewig: "Book Review: Apple Intelligence in the Enterprise" · Heise Developer

2025

Rodewig: "Switching to Passkeys: A Guide for App Developers" · Mac & i, Heise Verlag

2025

Rodewig: "TDD for Embedded Platforms — Practical Use and Framework Comparison" · Heise Developer

2024

Rodewig: "Intelligence for Developers: WWDC 2024 in Review" · Mac & i, Heise Verlag

2024

Rodewig: "Apple Intelligence: Behind Apple's AI Plans" · Mac & i, Heise Verlag

2024

Rodewig: "Developing GDPR-Compliant Apps" · Mac & i, Heise Verlag

2024

Rodewig: "Beyond Passwords: Using Passkeys in Custom Applications" · iX, Heise Verlag

2024

Rodewig: "Implementing Multi-Factor Authentication in the Enterprise" · iX, Heise Verlag

2024

Rodewig: "iMessage: How Contact Key Verification Works" · Mac & i, Heise Verlag

2023

Rodewig, Zimmermann: "Rapid Security Response for macOS and iOS" · Mac & i, Heise Verlag

2023

Rodewig: "Cryptography in Practice: Passwordless Login — Part 1 & 2" · Heise Developer

2022

Rodewig, Friedrich: "Cross-Platform Development with Flutter" · Mac & i, Heise Verlag

2020

Rodewig, Zimmermann: "iOS Apps Under Export Control" · Mac & i, Heise Verlag

2019

Rodewig: "Swift 5 — Highlights in Practice" · Mac & i, Heise Verlag

2019

Rodewig: "Strict Security Guards — Notarization & Hardened Runtime" · Mac & i, Heise Verlag

2019

Rodewig: "Uninvited Guests — Malware on the Mac" · Mac & i, Heise Verlag

2018

Rodewig: "Apps with Understanding — Natural Language Processing" · Mac & i, Heise Verlag

2018

Rodewig: "Shielded — The Security Architecture of macOS 10.13" · Mac & i, Heise Verlag

2016

Rodewig: "Practical Usage of Certificate Pinning in iOS Apps"

2016

Rodewig, Zimmermann: "Pencil Support in Custom Apps" · Mac & i, Heise Verlag

2016

Rodewig: "Developing Secure iOS Apps — Part 1 & 2" · Mac & i + Special Edition, Heise Verlag

2016

Rodewig, Zimmermann: "Differential Privacy" · c't & Mac & i, Heise Verlag

2016

Rodewig, Zimmermann: "Data Everywhere — Using CloudKit in Custom Apps" · Mac & i, Heise Verlag

2016

CVE-2016-1802 — Security vulnerability disclosure (iOS, watchOS, macOS, tvOS)

2015

Rodewig: "UI Testing with UIAutomation" · Mac & i, Heise Verlag

2015

Rodewig: "Data Security with Boxcryptor" · Mac & i, Heise Verlag

2015

Guest contribution on cybersecurity in VoiceCompass "Einfach anders arbeiten"

2013

Co-author: "Apps & Mobile Experience" guideline · BITKOM

2007

Rodewig: "Introduction to Source Code Analysis Methodology" · Hakin9

2007

Rodewig: "Threat Modeling" · Hakin9

2017

Programming Apps with Swift (2nd ed.)

Rodewig, Brunsmann, Hauser · Rheinwerk · 397 pages

2016

Programming Apps with Swift

Rodewig, Brunsmann, Hauser · Rheinwerk · 371 pages

2014

Developing iPhone and iPad Apps (2nd ed.)

Rodewig, Brunsmann · Galileo Press · 393 pages

2014

Programming Apps for iPhone and iPad (3rd ed.)

Rodewig, Wagner · Galileo Press · 1276 pages

2013

Programming Apps for iPhone and iPad (2nd ed.)

Rodewig, Wagner · Galileo Press · 1172 pages

2013

Developing iPhone and iPad Apps

Rodewig, Brunsmann · Galileo Press · 345 pages

2012

Programming Apps for iPhone and iPad

Rodewig, Wagner · Galileo Press · 1012 pages

2011

Setting Up and Administering Web Servers (2nd ed.)

Rodewig · Galileo Press · 497 pages

2011

Developing Apps for iPhone and iPad

Rodewig, Wagner · Galileo Press · 515 pages

2008

Setting Up and Administering Web Servers

Rodewig · Galileo Press · 420 pages

2006

Objective-C and Cocoa (2nd ed.)

Rodewig, Negm-Awad · SmartBooks · 920 pages

2006

Networking with Linux

Rodewig · SmartBooks · High availability, security & performance · 650 pages

2005

Objective-C and Cocoa

Rodewig · SmartBooks · Programming for Mac OS X · 544 pages

WDR

Home Office — But Secure! · WDR Angeklickt & Digitalistan

WDR

Hackers vs. Hackers · WDR Angeklickt

WDR

Security Vulnerabilities in WhatsApp · WDR Angeklickt

WDR

Reducing Bandwidth? Pure Activism · WDR Angeklickt & Digitalistan

WDR

Hack, Hack — Data Gone · WDR Cosmo

WDR

Making Your High-Tech Home Secure · WDR Angeklickt

Macoun

ARM Assembly for iOS Developers · Macoun Conference

Macoun

Security Made Simple · Macoun Conference

Contact
Appnö GmbH Erkrather Str. 401 40231 Düsseldorf, Germany
Managing Director Klaus Rodewig
Commercial Register Amtsgericht Düsseldorf · HRB 74943
VAT ID DE308226646

Appnö GmbH

Software · Security

Düsseldorf, Germany
New by Appnö By-Pass Our Solar System Simulator — Free on the App Store