Source URL: https://simonwillison.net/2025/Jun/16/100-percent/#atom-everything
Source: Simon Willison’s Weblog
Title: 100% effective
Feedly Summary: Every time I get into an online conversation about prompt injection it’s inevitable that someone will argue that a mitigation which works 99% of the time is still worthwhile because there’s no such thing as a security fix that is 100% guaranteed to work.
I don’t think that’s true.
If I use parameterized SQL queries my systems are 100% protected against SQL injection attacks.
If I make a mistake applying those and someone reports it to me I can fix that mistake and now I’m back up to 100%.
If our measures against SQL injection were only 99% effective none of our digital activities involving relational databases would be safe.
I don’t think it is unreasonable to want a security fix that, when applied correctly, works 100% of the time.
(I first argued a version of this back in September 2022 in You can’t solve AI security problems with more AI.)
Tags: sql-injection, security, prompt-injection
AI Summary and Description: Yes
Summary: The text presents a strong argument against accepting less-than-perfect security measures, particularly in the context of prompt injection and its comparison to SQL injection. It emphasizes the importance of achieving 100% effectiveness in security solutions.
Detailed Description: The author challenges the common narrative that a 99% effective security measure is acceptable. They draw a parallel with SQL injection protection, advocating for the idea that if proper security measures are followed, one can achieve total protection.
– **Key Argument**:
– The discussion revolves around the effectiveness of security measures and the common acceptance of imperfections.
– The author believes it is unreasonable to accept any level of risk when a definitive solution exists.
– **Comparative Analysis**:
– They point to parameterized SQL queries as an example of a security measure that can be fully effective if applied correctly.
– The text implies that unlike some security solutions like those used against prompt injection, SQL injection defenses can reach a standard of complete effectiveness.
– **Takeaway for Professionals**:
– The need for security professionals to strive for solutions that ensure absolute protection, rather than settling for measures that statistically reduce risk.
– A call to reconsider how security solutions are viewed within the industry, particularly as they pertain to emerging technological threats.
In conclusion, this analysis pieces together the importance of scrutinizing security measures in the ever-evolving landscape of cyber threats, underscoring the necessity for absolute effectiveness in security practices.