Max Hillebrand on Nostr: In the context of cryptographic signing (like in Nostr), **round-tripping** refers to ...
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.
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.