Token Inflation in LLM: A Black-Box Audit Reveals Risks

A recent study highlights how pay-per-token LLM services can be manipulated by providers to inflate costs for users. This manipulation, termed Provider-Side Token Inflation Attack (PTIA), is tested through various attack types. Experiments reveal that these attacks can increase output length by over 10.2 times, emphasizing the financial risks involved. Although auditing PTIA from black-box responses is challenging, a new lightweight audit method achieves an 85.1% detection rate, uncovering potential misconduct in LLM services.