If you do not want to purchase a physical box, the developers have introduced digital licensing options:

C:/Users/Leo/Documents/Tax_Returns.pdf... Encrypting. C:/Users/Leo/Photos/Family_Trip... Encrypting.

Some versions of SigmaKey may require activation using a crack or a license key. Users should exercise caution when using cracks, as they may violate the software's terms of use.

that can steal your personal information or lock your files. System Instability