How to confirm that two subscriptions are from the same user?

[caoyongfeng0214]

On iOS, each subscription has the same originalTransactionIdentifierIOS, which can be used to confirm whether it comes from the same user.

However, there is no similar identifier in the purchaseHistory and currentPurchase objects in Android.

Can purchaseToken be used to make this judgment?

If a user subscribes to "Subscription A" (paid monthly), and it automatically renews after one month, is the purchaseToken used during renewal the same as the previous purchaseToken?

If a user subscribes to "Subscription A" (paid monthly), and one month later he wants to change to "Subscription B" (paid annually), is the purchaseToken used during subscription to "Subscription B" the same as the previous purchaseToken?

Thanks.