File-chunk identification possibility

[shalnoff]

Is it possible to identify the file that chunk is owned (and vice versa)?

[RichardLitt]

I'm not sure. @diasdavid @whyrusleeping what do you think?

[whyrusleeping]

@shalnoff could you clarify what you mean?

[daviddias]

@shalnoff if your question is 'given a chunk, can I identify the file it belongs to, without any other information at all', the answer is no, you can't, that would violate the principle of a DAG.

[mcast]

@shalnoff if your question is 'given a chunk, can I identify the file it belongs to, without any other information at all', the answer is no, you can't, that would violate the principle of a DAG.

I would only add, "...unless you have some extra information". Would these methods work?

1. fetching the chunk's data, recognising some distinctive feature of its encoding. e.g. it's plain text, or gzipped text with a convenient block start; take five words and put them into a search engine to get the original.
2. enumerate (List all items stored on ipfs and corresponding hash value #155) a large enough swathe to discover (some of) the chunk's parents.
3. be in possession of some kind of reverse-lookup index, constructed from such enumeration

In a different chunking system, which could ride ipfs it is by design impossible to identify chunks.

[shalnoff]

Clear, that's what I'd like to clarify. Thank you (sorry for late reply)

[madavieb]

This issue has been moved to https://discuss.ipfs.io/t/file-chunk-identification-possibility/353.