Self-Destructing SMS. Checking if Third Parties Read Our SMS

Self-Destructing SMS

In the first part of this chapter, we discussed the security issues of SMS, in the second part we talked about how to send SMS anonymously, and now we will focus on protecting the messages themselves.

Today, almost every user’s phone has the ability to open links to view websites – this allows us to use disposable notes, just like we used for breaking information.

To create disposable notes, we will use the service privnote.com. Privnote allows you to create notes that are permanently destroyed after being read. We have already discussed how this service works in this chapter. You create a message through the Privnote service, and you send the recipient only the link to the disposable note.

The Privnote link consists of the website address/note identifier#client key. The client key is stored in the link as an anchor. The anchor is the part of the URL that comes after the # in the link and is never sent to the server (RFC on URL http://www.faqs.org/rfcs/rfc1808.html, section 2.4.1). The browser does not send this part of the link, and the server does not accept it, so the client key never leaves the client’s computer without their consent. The owners of Privnote theoretically cannot decrypt your note.

You are not obligated to use Privnote; there are many services with a similar algorithm, such as onetimesecret.com or tmwsd.ws.

A disposable note by itself will not protect you from interception and reading of SMS, but it will make it impossible for unnoticed reading of the note, because the final recipient will no longer be able to open the link if someone read it on the way to them. Additionally, storing the used disposable link to the note with the operator or on the phone does not pose a threat, as the note cannot be read a second time.

Protecting SMS from Interception

If you want to protect SMS from interception, when creating a disposable note, specify a password, without which viewing the hidden information will be impossible. Naturally, your interlocutor must know this password.