Can AI invent a new coded form of communication that only 2 people can understand ?

If you’re looking for a truly exclusive, two-person code that only your chosen recipient can crack, could an AI actually invent something beyond basic puzzles or toy ciphers? The catch: any custom code today risks being broken or shared—not because the idea itself is flawed, but because true secrecy requires more than just clever encoding.

Background

AI systems can generate novel ciphers or encoding schemes through text-based instructions, creating substitution tables, keyword triggers, or context-dependent transformations tailored to specific scenarios. For example, an AI might propose a cipher where letters are replaced based on a shared keyword, or where word meanings shift depending on an agreed-upon external cue. However, such systems remain vulnerable to classical attacks unless they integrate established cryptographic methods like encryption with pre-shared keys. Without these, custom codes are often classified as 'security through obscurity'—a term used in cryptography to describe systems that rely on secrecy of design rather than provable mathematical hardness. As of mid-2024, no publicly documented AI system has demonstrated the capacity to generate and deploy a cipher that guarantees exclusivity to two parties without additional cryptographic infrastructure. This limitation stems from the fact that any code, no matter how complex, can eventually be reverse-engineered if the underlying algorithm or shared secret is exposed. Thus, while AI can facilitate the creation of personalized coded forms of communication for educational or playful purposes, the sole reliance on these ciphers does not constitute a secure, future-proof communication channel in the cryptographic sense.