Dynamic Proof of Work Rate Limiting for Spam Mitigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for detecting and preventing spam messages rely on server analysis of message content, which is ineffective for encrypted messages and does not deter spammers, as they incur no computational cost and are not discouraged from sending spam.
Innovation Solution
Implementing a system that rate-limits message-sending clients based on dynamically calculated risk assessments by providing proof of work problems of varying difficulty, where suspected spammers are given harder problems to solve, increasing their computational cost and discouraging spamming, while normal users face easier challenges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the message service requires all clients to solve proof of work problems to send messages, then spam transmission is reduced, but legitimate message sending becomes slower and more resource-intensive
Solution Approach 1:
The system applies different proof of work difficulty levels to different clients based on their risk assessments. Low-risk clients (legitimate users) receive easier problems with lower computational requirements, while high-risk clients (suspected spammers) receive harder problems. This local differentiation allows the system to reduce spam without significantly impacting legitimate message sending performance.
Solution Approach 2:
The system dynamically adjusts the difficulty parameter of proof of work problems based on client risk profiles. By changing the computational difficulty parameter rather than applying a uniform threshold, the system can effectively rate-limit suspected spammers while maintaining acceptable message sending speeds for legitimate users.
2Measurement precision
If the message service analyzes every message to detect spam, then spam detection accuracy improves, but server resource consumption increases
Solution Approach 1:
The system performs preliminary risk assessment and proof of work verification before messages are fully processed and analyzed. By evaluating client risk levels in advance and requiring proof of work completion beforehand, the system filters out suspected spammers early in the process, preventing wasteful analysis of their messages and reducing overall server resource consumption.
Solution Approach 2:
The system extracts and evaluates specific risk indicators (message volume, frequency, client reputation) separately from full message analysis. This selective extraction of key risk factors allows the system to make quick spam likelihood determinations without analyzing every message content, thereby maintaining detection accuracy while reducing energy consumption.
3Reliability
If the message service quarantines suspected spam messages, then users are protected from spam, but spammers are not deterred from continuing to send spam
Solution Approach 1:
Instead of merely quarantining spam after it's sent, the system applies preliminary anti-action by requiring proof of work completion before messages are delivered. This creates a computational barrier that actively deters spammers in advance, increasing their resource costs and reducing their ability to persist in spam campaigns, while still maintaining user protection through the same mechanism.
Data Source
AI summary
Systems and methods are described for rate-limiting a message-sending client interacting with a message service based on dynamically calculated risk assessments of the probability that the client is, or is not, a sender of a spam messages. The message service sends a proof of work problem to a sending client device with a difficulty level that is related to a risk assessment that the client is a sender of spam messages. The message system limits the rate at which a known or suspected spammer can send messages by giving the known or suspected spammer client harder proof of work problems to solve, while minimizing the burden on normal users of the message system by given them easier proof of work problems to solve that can typically be solved by the client within the time that it takes to type a message.