Has it any advantage over an encryption with openssl for example?
Beside of its 'user friendly' UI there isn't an advantage.
Openssl is perfectly fine for that.
To encrypt it with AES for example:
openssl enc -aes-256-cbc -in un_encrypted.file -out encrypted.file
You will be prompted to enter a password.
If you chose to use an encryption with a private key instead of a password you should check if your entropy pool is 'filled enough'.
On linux:
cat /proc/sys/kernel/random/entropy_avail
If the number shown is bigger than 300-400 then your result will be 'random enough'.
Afterwards you could create your RSA private key with:
openssl genrsa -out private.pem 2048
and your public key with:
openssl rsa -in private.pem -out public.pem -outform PEM -pubout
Then to encrypt your file:
openssl rsautl -encrypt -inkey public.pem -pubin -in your_file.txt -out your_encrypted_file.ssl
and to decrypt afterwards:
openssl rsautl -decrypt -inkey private.pem -in file.ssl -out decrypted.txt
Key encryption gives you a higher grade of security regarding brute force / social engineering attacks.
Just make sure to keep your key at a safe place, with different backups.
But if you just want to encrypt it with a password thats not too risky either as long as the password is
random enough.
