This article demonstrates how to disable iOS backup encryption in iTunes.
Remove iPhone backup encryption with CopyTrans Shelbee
CopyTrans Shelbee allows you to remove iPhone backup encryption without the need for iTunes. To do so:
Run CopyTrans Shelbee and navigate to Backup > Full backup > Encryption.
Now click the “Remove” tab, enter the current password, click “Remove” and begin the backup by clicking “Start”.
NOTE: password will be removed after the backup begins.
How to turn off iOS backup encryption in iTunes
To disable the encryption of your iPhone, iPad, or iPod Touch backup in iTunes:
Connect your iOS device.
From the “Summary” tab of your iDevice settings in iTunes, un-check the “Encrypt iPhone backup” option.
When prompted, enter the encryption password and click “OK”.
iTunes will now create another backup of your iPhone, iPad, or iPod Touch which will not be encrypted.
This is how to disable iPhone backup encryption in iTunes.
TIP: If you forgot your backup password, please refer to this article: I forgot my iPhone backup password.