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I would like to transfer a 20+ GB file to a friend. I would like it to:

  1. Be fast
  2. Ensure data integrity
  3. Not require opening ports in either end's firewall
  4. Be free
  5. Not broadcast the file's existence to everyone on the Internet

I've looked a several technologies and nothing seems to fit:

For a file this size speed and data integrity are the most important. No one wants a 20 GB file to fail a MD5 check after spending two days downloading it. Is there anything that meets all these requirements?

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migrated from superuser.com Nov 22 '10 at 13:50

This question came from our site for computer enthusiasts and power users.

Bittorrent doesn't have to be public to everyone. If I remember, some clients allow you to create a private tracker, and only people getting your link would actually be able to download. Though I may be wrong –  Gnoupi Aug 26 '09 at 19:50
It would be nice to know more about the connections you and your friend use. Mostly their capacity in download and upload. Because typically, if the upload is really limited, you might consider a solution rather "hosting" on a third party server, which would then deliver the file faster to your friend. For you, no change, for him, less time spent downloading. –  Gnoupi Aug 26 '09 at 20:06
Not really a web app question, as most solutions require software installed on each machine - surprised this was migrated from superuser, as that's where it seems it would belong –  Josh Newman Jul 20 '11 at 20:05

17 Answers 17

First important think is "split to smaller pieces". Because if you get a bad checksum, you only download one piece again, no the whole file.

  1. create checksum for the whole file
  2. split to smaller pieces (100/500/1000 MB)
  3. create checksum for each piece
  4. send through the Internet

I think FTP is best, the only limitation is Internet connection.

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Note that I know 7zip (and maybe other compressions programs) have the option to split large files into multiple chunks, even without compressing them. –  tj111 Aug 26 '09 at 20:09
The "split into small parts and send" would definitely be my first choice. WinRar with quickpar Pars would be my recommendation. Allows repairs to be made should any rars become corrupted. A strong password would add further privacy. –  RJFalconer Aug 26 '09 at 20:32
@tj111 : Most of archiving programs have this option now, I think. (Winzip, winrar, too, for example) –  Gnoupi Aug 26 '09 at 20:33
Note that using a download manager to retrieve the files from the FTP solution would solve most of issues of "pause/continue" and data integrity. –  Gnoupi Aug 26 '09 at 20:41
This "splitting into pieces" should never be done by the user, it should be handled by the protocol itself (such as bittorrent). –  Lo'oris Nov 17 '10 at 15:08

Archive it and split it, then burn it on several DVDs. Then, send by the regular mail. :-)

  1. It can be fast and secure, depending on how you send it.
  2. If the package is correctly protected, it also ensures data integrity (as long as the dvds are without scratches, and in one piece, the data will most like be ok)
  3. for sure it won't require to mess with your firewall.
  4. It's not free, that's the only drawback, but it's probably a quite small price.
  5. It won't broadcast the existence of the file on the Internet either.

Of course, that requires your friend to preferably not live on the other side of the planet.

But besides, when seeing the sending speed of some connections, it would be almost faster and safer this way.

Edit : I'm actually off-topic, I just noticed the question states "over the Internet". Consider my solution only as "last resort", then.

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Even though the OP suggests what they think part of the solution should be, that shouldn't stop you posting an answer that basically says "don't do it that way, do it this way". As long as you give your reasons it should be accepted. This has recently been discussed on meta (which I can't find right now) –  ChrisF Aug 26 '09 at 20:12
Hmmm, good to know. –  Gnoupi Aug 26 '09 at 20:13
By "accepted" I mean "allowed", not giving you 15 rep points! –  ChrisF Aug 26 '09 at 20:14
Yes, of course. But I guess indeed it has to be explained. Not a "why doing it on linux do it with Windows". –  Gnoupi Aug 26 '09 at 20:16
@ChrisF: Agreed. @Gnoupi: As they say, never underestimate the bandwidth of a station wagon full of backup tapes. The latency is horrendous, though. :) –  Alexander Burke Mar 16 '10 at 0:10

Use snail mail to send a 32 GB SDHC to your friend.

This is not free though.

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Close to my solution, but I think the memory card would indeed be safer and lighter to send by regular mail. Although the cost would be probably higher. –  Gnoupi Aug 26 '09 at 20:39

Quoting Andrew Tanenbaum:

Never underestimate the bandwidth of a truck full of tapes hurling down the highway

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heh. great quote. –  Epaga Nov 5 '09 at 13:54
you get great bandwidth, but the latency sucks –  davr Apr 8 '10 at 17:49

Set up IIS on your box and drop the file in. Configure IIS only to accept connections from your IP and their IP. Give them the URL via probably your direct IP address. Note all versions of Windows since 2000 come with IIS (At least the ones people actually use. You may need to put your install disc in).

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Have a look at Hamachi or one of the other alternatives on the Wikipedia page. I have used Hamachi in the past, and I think it'll fit your requirements well.

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Though with the encryption made by the VPN, it may not be "fast". But it answers most of the other concerns, though. –  Gnoupi Aug 26 '09 at 20:22
Speed is relative. Should be faster than snail mail under normal circumstances :) –  nagul Aug 26 '09 at 23:03

Install Waste on both machines. You do have to open ports, but you can choose port numbers and the traffic is public-key encrypted.

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You already mentioned what's likely the best solution: SFTP (or scp)

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Use BitTorrent if you can wait a couple of days. uTorrent is a lightweight client that would allow you to create your own torrent file. Then send the file to the other side, have the other person install uTorrent too and leave them up. The process may not start instantly, but it'll get uploaded eventually.

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You can try Files over Miles. I have used it a few times but never on such large files. It is very easy to set up. It can recover from a short dropped connection but I don't know how it would handle 20 GB files.

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Looks superficially similar to JetBytes. Though I don't recall JetBytes ever being able to recover from a dropped connection. –  Kenneth Cochran Aug 26 '09 at 19:57
Upon looking at the faq, it won't work. Because it uses Flash, its limited to files smaller than the available amount of ram. –  Kenneth Cochran Aug 26 '09 at 20:00

OneSwarm friend-2-friend sharing, not sure about 3. though, it's similar to BitTorrent.

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You could have a look at HFS (Http File Server) which runs a web server from your computer enabling others to download via their browser.

I'd split the file up first as recommended by @MicTech.

Bear in mind that the upload bandwidth from your PC is likely to be the killer. My "up to" 10Mbit/sec home connection has < 500Kbit/sec upload bandwidth so 20GB would take about 4 days to transfer.

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If you are behind a router you will need to do some port forwarding.

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http://click2copy.com - this is the only one service in the internet, that sends file browser-to-browser and not browser-server-browser. So, it establishes the direct connections between two computers even if they are behind the NAT.

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Note: the user Ilya is the owner of click2copy –  ChrisF Nov 22 '10 at 14:08

How about streamfile - or something similar ?

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That service only allows for max size of 150 Mb. –  Eugene Mar 16 '10 at 0:07
While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. –  user221287 Dec 4 '12 at 8:38

http://sendoid.com - if you use the Adobe Air app version, it apparently supports unlimited file sizes

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http://web.synametrics.com/SynaMan.htm - "SynaMan is an innovative, all-in-one web-based remote file manager allowing users to upload or download files from any machine, anywhere on the Internet. It is secure and is easy to install on any machine running any operating system."

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