I use Duplicati and Jottacloud for off-site backups. Now that some friends have gigabit fibre, I’m interested in allowing us to offer backups for each other.
What is the recommended way to do this? I think we are all behind CG-NAT now, with IPv6 support.
Obviously security is the main thing, but ideally it should be easy to set up and use. Backups should be automatic. I’m happy with Duplicati, but open to alternatives.
not the best idea even for friends.
you have no idea what people have stored on there pc’s.
add in things like duplicati offer aes 256 encryption, means theres no way for you to know what a file is if they decide to use it.
and as its on your storage, you would be legally accountable for it if the law comes knocking.
i know, oh its people i know, they would never.
yep! that’s the sad thing about it.
sometimes its the people you know. 
You kind of have choices.
For 1 and 2 they can do rclone… for 3, you’re giving them compute, but it’s very limited and can be easily firewalled off to make it a low value target.
edit: see OpenSSH/Cookbook/File Transfer with SFTP - Wikibooks, open books for an open world … there’s how to setup sftp-only accounts there.
If you have no way to see the contents due to encryption beyond your control, then no, you have no particular legal responsibility for it.
There is some slim risk the cops will come knocking with a warrant and seize all your computers, taking quite some time for you to get them back, but that’s exceptionally unlikely unless you’re providing a public file sharing service, or your friends are big time criminals.
tell that to kim dot com.
if your hosting the files your legally responsible for them under things like gdpr.
yeah its not as slim a risk as you think. they dont have to be big time criminals just deviants.
and while we all know which of our mates are crims. its often a shock to find out someone you know is a predator.
anyhoo. im not saying dont do it, just know the risks… all of em.
Megaupload is a special case. It was designed to be a popular file sharing service, and its design did not work as a backup service. There are a number of issues with the way they designed and ran their site which resulted in just that site, and not all others, being held legally responsible:
OP made no mention of offering public file sharing. Many backup services exist, big and small, which do not run into any particular legal issues. If your view of the law was accurate, none of them would possibly survive.
Isn’t MEGA still up and not under fire?
And MegaUpload came under fire because the files were publicly available, and therefore could be known to the general public, and it was a file sharing site, for sharing files, which incentivized file sharing and profited off the sharing of files.
A private backup is a fairly different case, as the files are not publicly available, and if encrypted correctly, not even available to you. If you have no access to the contents of the data, the data it’s self is gibberish. However, as MegaUpload provided access to the data to anyone who could load the webpage, it was accessible for the site owner within reason, as it was accessible to the broader public.
Encrypted data is just a type of gibberish you combine with a magic gibberish to make something sensible. You can, in fact, turn any data into any other data with the correct key. Not that I expect a court of law to understand that, but I could take any illicit file and make a program to encrypt that into any harmless file and a key that can be used to reverse that process. If encrypted data that you have no access to the unencrypted contents of in any way can make you a criminal, we are all guilty.
nope megaupload is gone. replaced by mega hosted where it cant be tuched my the american movie association or the fbi.
as for the rest im perfectly well aware…
my point is, even if you think you know someone, be careful…
Thanks for the replies. The main issue is how to do it securely, and from behind CG-NAT.
I guess I’d need something like the old dynamic DNS, but for IPv6?
Then secure a server of some kind.
You can go IPv6 or Tailscale is usually my go-to when working behind CGNAT.
Tailscale ftw for NAT traversal.
One other entirely different kind of thing that comes to mind is Sia and Storj and other “decentralized storage”.
The key difference is that over there you’re putting your spare space on the open market and cash is involved. When doing basic sftp for your friend, they might be ok with you losing their backups, drives die stuff happens and so on, it all takes a while but statistically more often than not they can make new backups. With Sia, you lose money if you drop data, but you don’t pay for storage (as much) if someone drops your data… but your “friend pool” ends up being much larger.
If your data is fairly immutable and intended to be long lived, there are some very wide encodings you could use - imagine sharding data into 300 data chunks, and then putting 30 recovery chunks on there. It’s only +10% space blowup and odds of losing data are tiny.
Thanks. The Tailscale free tier seems like it would work for us. I will investigate.
Under GDPR, no.
Material Scope 2 C, while running an HPC-cluster for a hobby in the basement may be pushing the meaning of household use, as long as it is decidedly family&friends, then in GDPR terms, such a “backup space” would be alright.
Valid points. Plus, you will be woken at 3AM some evening when they need something now!
Depends on the jurisdiction, but I’d be more concerned over having my gear seized and held in an evidence locker for several years. The chances of ever getting it back is zero.
Never build computers or store data from friends. You’ll sleep much better.
If it’s on your system, you could be liable in full, Unless you can prove it is someone elses stuff.
Same with stolen goods.
But easier to prove it is other peoples (logs, permissions, accounts, created-by etc)
Otherwise sickos would just claim “my mate must have put that bad stuff there”…
Hosting places on the other hand, have an obligation not to share info without warrants etc.
But as far as I know, thefe is no official list of “actual” hosting places, so would be up to the legal team to show you have a system in okace to hols their illicit stuff, and that it is their not yours.
Also, phone backups, might have pics of their kids, which are innocent and fine for the actual parents to take and hold, but distribution could be… problematic, legally…
So if the freind encrypts it before sending, and does not share a key, then no access.
In the UK, the courts can hold you indefinitely until you give the key (up to 30/90 days at a time?)
And if you dont have the key, you better hope the share the key and dont have dodgy suff, if you cant prove the stuff is from others
Some programs can set up VPNs through CG-NAT easily when doing everything through ipv4 if that is what you want to stick with. But if you have ipv6 also and are comfortable with it then you can also bypass the NAT stuff by just using that. OpenVPN supports ipv6. You could set up your backup programs to run through the VPN tunnel
In the USSA, sure, in Europe, I think it’s less likely they just confiscate whatever.
As for backups, intermit.tech did a good guide on (minio) S3 + restic. Restic encrypts data client-side and S3 is a better option than (S)FTP when it comes to people accessing your hardware, as it’s solely limited to the object storage (you could chroot sftp, but eh).
That way, even if someone’s hardware gets seized, your data is still safe. I’d personally recommend that each of you buys their own SBC and preferred size HDDs and give it to each other.
If hypothetically one of you is a criminal master mind and gets raided, it would be your device that gets seized, with your encrypted data. That means your backup server is completely lost. Their backup server is still safe. You might get knock for an investigation with a warrant, but if you don’t live in burgerland, I kinda doubt you’ll have to worry about all your devices getting seized.
If colocation is an option, you can all put some money down for a 1U very low-power server and put it in a data center and it might be more reasonable than each of you having devices in each other’s house. It is still a risk, but much lower than having someone connect straight to you.
But this setup was planned as so, because you all would have fast internet at home. Talk to your ISP, some ISPs offer colocation services. If all of you share the same large ISP, it’ll probably be better than going to each other’s home internet. If you don’t share ISPs, going to each other’s internet would not be ideal anyway, so colocating makes even more sense.
Besides the hardware cost, colocation costs around 250 euros (last I checked was 3 years ago I think, prices might’ve gone up). That’d make 4 people pay about 65 euros a month. With 22TB drives, you can get a stripped mirror with 44TB usable capacity, which can take you a long way (I mean, 11TB of data for each individual’s most important data?). In minio I think you get the option to allocate only a certain amount to each bucket.
If you split it 6 way, it goes to about 42 / month for about 7TB ea.
Because you have IPv6 access, I’d avoid tailscale altogether. You have a world addressable IP address. Use that if your networks all have ipv6 enabled. Maybe slap a DynDNS like duckdns or no-ip, no matter which option (home hosting or colocating) you pick.
They dont seize everything, and a couple years later return what is confirmed as no forrensic benefit agsinst you?
I mean, If I were a plod, I would grab everything, and put it in the back of a loooong cue, pushing mobile phones to the urgent list…
But we dont have 4th ammendment, so warrants can be pretty broad
Not in the US. Despite being a criminal investigation, if they got nothing on you, it would be counted as “”“civil asset forfeiture”“” where you don’t get charged with anything, but your property gets charged with being part of a crime and taken in as “”“evidence.”“” It’s a workaround to just steal stuff (in the US, this type of property confiscation is totaling a larger amount of money than private stealing, it’s how many LEO Departments pay their bills - plus, some of these public servants can get to keep some of the stuff they want, particularly automotive vehicles “charged with a crime”).
They sell the property for revenue at a large discount. If it’s a real criminal investigation, they might try to get the data off of electronic devices before trying to sell it, or even use the hardware in-house.
This literally bypasses any written legislation about having warrants to investigate or confiscate things.