I chatted with a staff from Google, about the encryption systems that Google applies to customer data. I was amazed that the personnel said Google does not apply any encryption methods to user data. Data is saved as it were on Google drive.
I went on to check on Onedrive, and realized also that Microsoft does not have an encryption system applied to cloud stored data on Onedrive.
Then, Dropbox is the one who applies encryption to data. However, Dropbox keeps the decryption key within the server and does the decryption by themselves when a user downloads their data.
Please can someone throw more light as to why all these? I thought the cloud providers were supposed to encrypt all data stored on their servers? And, for any access to the encrypted file, a decryption key is applied?