In the context of cryptographic signing (like in Nostr), **round-tripping** refers to the ability to serialize a data structure (e.g., JSON) into a string, then deserialize it back into an identical data structure **without any changes to formatting, key ordering, whitespace, or other non-semantic details**. The problem arises because many JSON libraries/implementations handle serialization differently (e.g., adding/removing spaces, reordering keys, varying number representations). If a protocol like Nostr requires signing a JSON string, but doesn’t enforce **strict ECMA-262 serialization rules**, two implementations might produce *different string representations* of the *same logical data*, leading to **failed signature verifications**. For example: 1. Implementation A serializes `{"a":1,"b":2}` with spaces: `{ "a": 1, "b": 2 }` 2. Implementation B serializes the same object with no spaces and reversed keys: `{"b":2,"a":1}` 3. The resulting strings differ → hashes differ → signatures mismatch, even though the data is "logically" identical. This is why the Nostr ecosystem has faced interoperability issues – its original spec naively assumed JSON implementations would naturally agree on serialization details, which they don’t. Crypto protocols *must* standardize serialization rigorously (as ECMA-262 does) to avoid these round-tripping pitfalls.

But why does it matter, whatever is the serialized JSON which is signed is what should be regarded as the "true" value, also post deserialization why does it matter if there is a difference in the order. The protocol itself doesn't provide any guarantees nor should it look to provide any guarantees post deserialization?