Replace Dropbox with BitTorrent Sync and a Raspberry Pi

Re:Replace Dropbox with BitTorrent Sync and a Raspberry Pi by TheCraiggers on Friday July 19, 2013 @02:26PM (#6071943)

The particulars of the BT protocol are beyond me, but I thought it would already do a compare between the copy you had and the one on the external server, and only send the relevant bytes to bring everything up to sync again.

Between that and a "compare timestamps to figure out the newest file" I wouldn't think it would be that hard to re-create? What am I missing here?

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Re:Replace Dropbox with BitTorrent Sync and a Raspberry Pi by Osiris on Friday July 19, 2013 @04:17PM (#6072687)

BitTorrent creates a hashes of your file. The file is broken down into certain size chunks and hashes taken of each chunk. If you already have a piece with a given hash, you won't download it. If a hash differs, it'll be transmitted. The receiver verifies the hash. If it fails it re-requests that piece.

I assume the sync protocol works the same. It hashes the file, checks if any chunks have changed, sends the hash meta-data to the recipient, who then requests and pieces that have changed.

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Re:Replace Dropbox with BitTorrent Sync and a Raspberry Pi by dman on Friday July 19, 2013 @04:26PM (#6072751)

What about hash collisions?

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Re:Replace Dropbox with BitTorrent Sync and a Raspberry Pi by tokenizerrr on Friday July 19, 2013 @05:34PM (#6073090)

SHA-2 has no collisions found as of yet [1]. The collision attacks on md5 required a lot of junk data, so not sure how much of a problem that would be.

[1]: https://en.wikipedia.org/wiki/SHA-2#Comparison_of_SHA_functi...

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