Putting any sort of content in electronic form and giving any outside access means that it will be copied against your wishes. There is next to nothing you can do about this; multinational IP companies have tried and only succeeded in limited ways.
If you want only a paying customer base to be able to access your magazine, you can put it behnd a paywall or subscription wall, and take some steps to make it difficult to copy, download or share direct links with. (For example, I could post a link to a newspaper or magazine with a paywall, but you would be blocked from any access, or anything but preview access, unless you also were a subscriber.)
But unless you're willing to up your website hosting and functionality to a full paywall system, anyone who has the URL, or gets it from a share or just a copy from the address bar, is going to be able to access the content.
This has nothing to do with Adobe or ID or the tools that enable simple "publish to web" functionality, though. You need someone with web back end/security design chops.
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