Editing P2p mobile carriers (section)

= 9. Preventing unintended communications =

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== 9.1. SMS messages meant for the seller ==

SMS messages received in this system will be insecure because buyers will be able to receive SMS messages intended for the seller. Sadly, this is not that much different to how SMS already works [sim-cloning]. Attackers with S7 access can intercept SMS messages easily, and other attacks only serve to make this easier [imsi-catcher].

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== 9.2. Calls meant for the seller ==

The buyer can also receive calls intended for the seller. The simplest solution is to have a separate plan for receiving personal calls and SMS that isn’t used in the decentralized system.

In practice, eSIM chips support multiple plans, although a program that shares mobile service will need to virtualize most of it. At least with eSIM the account setup will be easy and it won’t become a huge barrier to entry.

It’s possible that secret contracts can be used as an alternative solution to the unintended communications problem. For instance: if incoming calls or SMS messages are delivered using the ciphering key then a custom interface defines who can read them (just like the integrity key).

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