The BSI has conducted studies and analyses on the security and verifiability of online elections.

Project Market and vulnerability analysis of online voting products

A comprehensive market and security analysis of currently available online voting products was carried out as part of the Market and Vulnerability Analysis of Online Voting Products (MaSiOWa) project. The result of this analysis is a detailed picture of the state of IT security in this area. The results have been incorporated into the technical guidelines and protection profiles for online voting.

Unfortunately it was not possible to name all of the product owners involved in the project in the final report, as some of them did not give an explicit consent. You can find the final report here (german).

Study on end-to-end verifiability methods for online elections

In the project End-to-end verifiability methods for online elections (StuVe), the main cryptographic and technical methods for implementing end-to-end verifiability in online elections were identified in an in-depth market and literature analysis. A selection of these was comprehensively described, analyzed and evaluated using specially developed objective evaluation criteria. The study is available for download here.