[hecturchi]

The content ID is not the hash of the content, it is the hash of the root of the Merkle DAG that carries the content.

Doing it like that has many advantages, like being able to verify hashes as small blocks are downloaded and not after downloading a huge file. Being able to de-duplicate data, being able to represent files, folders and any type of linked content-addressed data structure.

As long as your content is under 4MiB you can opt out of all this and have a content ID that is exactly the hash of the content.

[anonymousnotme]

As I just replied to "cle", some disadvantages doing the way that it is because one can't predict what content ID would be produced. Perhaps the hash of the entire contents of the file could point the hash that is current the content ID would solve this issue. To me, IPFS does not seem useful unless this issue is solved. Also, multiple hashes (different algorithms) of the file could point to the content ID/merkle DAG; so if both SHA2 and SHA3 were both used and one of them had a security issues, then just use the one that is OK.