Today I am launching Number Protector, a service that provides dedicated phone numbers for anonymously receiving SMS messages directly to you shielded wallet via encrypted memo.
Important note: Per the discussion below, I am no longer using the term “anonymous” to describe this service. This service does not provide anonymity. How the customer uses the phone number may allow someone to connect the customer’s true identity with the phone number. Thank you to @sarahjamielewis for the helpful feedback on this issue.
One of the targeted use cases is anonymously signing up for services like Telegram. Telegram requires you to provide a phone number during the sign up process, which it uses to send you a verification code via SMS. To preserve your anonymity, you can provide Telegram your Number Protector phone number and receive the verification code directly to your shielded wallet via encrypted memo.
(Note that I haven’t used the word “privacy”. My understanding is that SMS messages are not encrypted, so you should not use SMS for communications that require privacy.)
Number Protector supports both Ycash and Zcash. To respect the norms of this forum, this post will be focused on Number Protector’s support for Zcash. (If you have a question about Number Protector’s support for Ycash, post it on the dedicated Ycash thread.)
The price is denominated in crypto, not fiat, and expires at a given block height. At the time of this post, the price for one year of service is 1 ZEC, and this price is good until block height 875,000 (approximately June 21, 2020). After block height 875,000, visit numberprotector.com for the current price.
Obtaining a Number Protector phone number
Go to https://www.numberprotector.com/#zec and look up the current annual price for service.
Let’s say the current annual price for service is X ZEC. Send at least X ZEC to:
and in the memo field of the transaction put the shielded Sapling address that you want your SMS messages delivered to. Don’t forget to put your address in the memo field!
You can purchase more than one year of service by sending any amount of ZEC greater than X ZEC. For example, if you send 2.25X ZEC, you are purchasing 2.25 years of service.
In a few minutes, you’ll receive your dedicated Number Protector phone number (via an encrypted memo). You will also receive a unique customer service shielded address that you can use to anonymously communicate with me about your number. It is very important that you keep this address secret because whoever knows it can make changes to your Number Protector service.
Whenever you need to receive an SMS message but want to keep your real cell phone number private, provide your Number Protector phone number instead.
Receive your SMS messages directly to your shielded Zcash wallet
Let me know if you have any feedback or questions.