Multi-Factor Protection From Unwanted Calls

This is a proposed solution to the problem of illegal robocalls and other unwanted calls in the global voice telephone network.

This proposal consists of three techniques in combination:

• Transfer of a monetary deposit using a micropayment service prior to call completion, performed at the Service Provider level transparent to the caller and recipient. If a recipient declares the call to be an unwelcome call, the caller’s deposit is forfeit. (Micropayment can be replaced by token exchange for a non-monetary system)
• A Subscriber-controlled whitelist allows callers to bypass the deposit requirement.
• A Human-interactive proof (HIP) task, suitable for telephone users, defeats automated calls with reasonable caller requirements.

These techniques have complementary strengths. This Proposal combines the three techniques for a robust and highly configurable system.

Key features of this Proposal are:

• Recognizes that there are legitimate uses of bulk calling operations, and such callers are not penalized or encumbered.
• Can provide a "guarantee" - the deposit forfeited by the Caller can be a payment to the Recipient, proving a monetary compensation for the unwanted call, and incentivizing the user to take action on unwanted calls.
• No change to the act of making a call; the process is transparent to legitimate users.
• No change is required on receiving a call - an optional action by the recipient is only taken to indicate that a call was a robocall or other unwelcome call.
• This proposal protects legitimate bulk callers and their call recipients from a class of exploits (“honeypot” exploits) – these are actions taken by malicious users to improperly cause others to incur penalties.
• No central authority required to determine whether a caller is making unwelcome or illegal calls. No policies to enforce, no costly identity verification or user screening. No outside enforcement mechanism, no judgments to be contested.
• Works with traditional phone end user equipment; does not require cell phone or additional phone capability. Changes are at the Service Provider level.