You just can't make changes to the encryption library without releasing those changes. Actually, you can make changes to GPL software without releasing those c

You just can't make changes to the encryption library without releasing those changes. Actually, you can make changes to GPL software without releasing those changes. The main restriction of the GPL is that if you distribute the software, you have to distribute the source too. But you have the freedom to do any changes and keep them to yourself without distributing anything.