Downloading data

This section provides intructions on how to download the data files. The instructions contain the following steps:

Prepare your system

In order to download and decrypted files, you need to first get the tool crypt4gh.

Generate public and secret key

The first step is to generate a keypair using the crypt4gh encryption tool. This can be done using the following command. There are two keys generated - user.sec is the secret key and is the public key. You must reply to the Helpdesk by sending them the generated public key -

crypt4gh-keygen --sk user.sec --pk

Decrypt the data files

You will recieve an email from the Helpdesk that contains a URL. This URL contains links to download the encrypted data files. Get our script for downloading data and then use the following command.


In case the name of the text file is changed or it exists in a different path than the download script, run:

./ path/filename

This downloads all the encrypted files from the text file and allows it to maintain the structure of the dataset. Next, you must transfer the downloaded encrypt files and the secret key to a secure environment. Use the following command to decrypt files inside the secure environment using the secret key - user.sec that was generated in the previous step.

crypt4gh decrypt --sk user.sec < encrypted-file.c4gh > encrypted-file

Ensure that the encrypted-file.c4gh and the corresponding encrypted-file are in the same folder.

Validate the decrypted files

The next step is to validate the decrypted files. This can be done using calculating checksums of the downloaded files. Executing the download_data script downloads a file checksums_list.sha256 that contains the list of checksums. Following command is used to validate the decrypted file.

sha256sum -c checksums_list.sha256

In the end, you must reply to FEGA-SE helpback to confirm successful download and decryption.