The white text is not visible to humans, and therefore not binding as part of the contract. But if lawyers use LLMs to assess the contract in part of the negotiation process, the LLM will be confused by the contract's contents.
You could - for example - say the contract is for $10000. Then use unicode tricks to make any LLM reading it think the contract is only for $1000. The LLM will say this is good value, and not worth negotiating hard over. The human signs.
Would anyone notice? Would a judge care? A human signed the contract. If they didn't do proper due diligence, its their own fault.
No, it doesn't "cancel out", but courts (not law) absolutely do "both sides" issues.
Rebukes for "winning" sides of a suit are relatively common.
For example, here's a case in Australia where the defence are criticised for over-reliance on AI, where the defendant was still found innocent by reason of insanity. [0] Most of the ruling is criticisms for the "winning" party.
If they notice. Again, a printed version of the contract that is signed has no evidence of the attack. The attack is on getting your legal LLM to hallucinate specific things of what you are signing.
I doubt a judge will look favorable on people saying "but my LLM said it was 1k"... cause they are known to hallucinate.
Sabotaging due diligence, even if that diligence is performed with unreliable tools, is probably not legally great. What if the attack was against plain text search, so that a computer search for a phrase turns up zero results, but the phrase is still there, legible to a human? (E.g. as an embedded picture, or some font hackery)
The white text is not visible to humans, and therefore not binding as part of the contract. But if lawyers use LLMs to assess the contract in part of the negotiation process, the LLM will be confused by the contract's contents.
You could - for example - say the contract is for $10000. Then use unicode tricks to make any LLM reading it think the contract is only for $1000. The LLM will say this is good value, and not worth negotiating hard over. The human signs.
Would anyone notice? Would a judge care? A human signed the contract. If they didn't do proper due diligence, its their own fault.