How to unencrypt google spreadsheet?

If I understand correctly, you want to decrypt the encrypted data in your google spreadsheet that is connected to jotform? Unfortunately, decryption is not possible in the Google Spreadsheet Integration. The only workaround I could suggest would be to access the form submissions page, upload the key to decrypt the data and manually export it to excel. Otherwise, if you want to use the Google Spreadsheet integration, you will have to disable the encryption on your form.