Handout for teachers

What is it about?

Thesis with a non-disclosure agreement (nda) may not be made accessible to third parties. Only persons directly involved in the processing of the examination may have access to the work. In order to be able to guarantee this protection for digitally submitted theses as well, encryption techniques must be used, especially so-called asymmetric encryption (public key method).

How does asymmetric encryption work?

This procedure is based on two keys that belong together, referred to here as key A and key B for the time being. They are generated as a related key pair and have the following properties:

1. what was encrypted with key A can be decrypted exclusively with key B. Key B can also exclusively decrypt files that were encrypted with key A.

2. what was encrypted with key B can be decrypted exclusively with key A. Key A can also exclusively decrypt files that were encrypted with key B.

You can generate such a key pair for yourself. One key (e.g., key A) is called the public key, and the other (key B) is called the private key.

The private key remains with you and may only be used by you. This is why you must protect this key with a password (passphrase) as soon as it is generated. Only someone who has this password can work with your private key.

The public key can be issued at will, for example by mail, or also published on the website. We use our employee database for this purpose, where you can find the public key under "more information...". You can find an example if you look at the entry for the university in the BeschäftigtenDB (enter first or last name "university", click "more information...").

What do I need to prepare?

If you do not have a key pair yet

Step 1: If you don't have a key pair yet, you can generate one here. To do so, please go to the "Key pair generator" subpage. On the page you will be asked for your name, your university email address and for a password for the private key. You can find the key pair generator here:

Step2: Please make a backup copy of the key pair and save the password for the private key separately. If you lose the private key or its password, you also lose the ability to decrypt the thesis.

If you want to have your public key entered in the "Beschäftigten-Datenbank"

To register in the employee database, use the following form:

Alternatively, send their public key directly to the person who is to send them an encrypted document.

How can I decrypt a file that was secured with my public key?

You need three things: the file to decrypt, your private key and the password for it (passphrase). To decrypt, go to the decryption website, upload the file to be decrypted and your private key there and enter the passphrase. Then click on "Decrypt" and after a short time the decrypted file will be placed in your download directory.