Johannes Zweng

Curious, interested in technology, open minded...

Interests:

See the list of some public postings and public contributions to see what caught my attention over time.

⚡ Bitcoin Lightning Network ⚡
Bitcoin (learning about Bitcoin since 2011, member of Bitcoin Austria since 2013)
Ethereum Virtual Machine, EVM Bytecode, Solidity
NFC applications
EMV banking cards, ISO 7816-4 and other smartcard stuff
SMS (Etsi GSM 03.40)
open source software, strong interest in security
staying curious...

Short bio:

Master's degree in Software Engineering & Internet Computing at TU Vienna
20 years of experience as software engineer
Working as senior developer at Coinfinity

Some fun projects:

SMS Sent Time, app for adding the real sent time of an SMS to the message (no longer working since changes in Android 4.4) (see this posting for background information)
Xposed module to allow sending of arbitrary low-level SMS PDU packets (Github, also adopted by HushSMS (not my project))
Reading transaction log data from NFC banking cards: Github, presentation at IIR Cashless Payments 2014, press coverage
Override SIM Secure Element Access Control of the OpenMobile API (to analyze SIM-based mobile payment chips): posting, Github
Analyzing how Flickercode for CardTAN banking works: posting, Demopage
Analyzing how to get Infrared working under AOSP on phones using QuickSet SDK IR blasters: Xda-Thread, Xposed Module
Checking EMV card keys for ROCA vulnerability: posting, Github
Modify NFC Card emulation AID Routing on Android, to catch ISO 7816-4 SELECT commands for all AIDs (for analyzing): Github Xda-Thread
2nd place at 2018 Smart-Public-Life-Hackathon in St. Pölten: Smart Parking proof-of-concept, using Bitcoin Lightning payments combined with license plate recognition: with Rene Kapusta, Christina Hauk, Sabrina Menger and Patrick Lamplmair
Presentation at BlockchainHub Graz: Introduction into "Atomic Swaps" (and HTLCs) (video available here, talk starting at 6:49)
Presentation (in german) for colleagues at Coinfinity: Introduction into Taproot and Schnorr (zoom recording available here, talk starting at 6:49)
proof of concept: Sending ETH to many destinations in a single transaction: ETH Batch Sending tool, Github

Online:

Twitter, Github, Bitcoin Stackexchange, XDA Developers

Contact information:

Mobile phone:	+4369911398186
Mail:	johannes [at] zweng [dot] at
Threema ID:	QR Code (B4U8 74PZ)
Keybase.io:	johnzweng
PGP Key (private):	C6C009F49B46AB71.asc Import the key: curl https://johannes.zweng.at/C6C009F49B46AB71.asc \| gpg --import
PGP Key (work E-Mail):	4079598C7015119C.asc Import the key: curl https://johannes.zweng.at/4079598C7015119C.asc \| gpg --import