The prototype of a bitcoin wallet with two-factor authentication and verification over a seperate channel. This prototype uses a modified version of the two-party DSA signature protocol by MacKenzie and Reiter.
Further information can be found in the article Two-factor authentication for the bitcoin protocol by Christopher Mann and Daniel Loebenberger (https://eprint.iacr.org/2014/629.pdf). For a detailed description refer to the master thesis by Christopher Mann BitcoinTwoFactorAuth.pdf.
This is a prototype. Do NOT use it for storing your real Bitcoins.