One-Time Cloud Backup of Archives

Do you have a laptop? Can you have two backup disks, one at home and one at work? Or transport backup disks between home and work? A one-time backup will be less valuable to you as time goes on, so this needs to be a habit rather than an event. You’ll also be continually testing your two backups that way.

Zip encryption is pretty crap. Use http://www.macupdate.com/app/mac/19139/ez7z instead; encrypted 7zip archives use proper AES256 encryption as well as compressing text better than Zip does.

Also, I doubt you'll find more cost-effective and convenient long term fireproofing for large amounts of old stuff than a couple of external hard drives kept in a different building.

10 GB of space on Crashplan can be https://www.crashplan.com/consumer/store.vtl. The http://www.newegg.com/Store/SubCategory.aspx?SubCategory=414&name=External-Hard-Drives&Order=PRICE. If you buy 3 years of Crashplan at a time, that's $59. And if you need more than $10 GB of space, you can unlimited space on Crashplan for $50/yr (or $40/yr if you buy 3 years at once). I mean, it sounds like your plan will work as long as your files compress down to < 12 GB. But what happens when Microsoft or Google changes something about their service? And are you going to re-zip and re-upload all of this stuff over and over again when it changes? If you're worried about privacy and uploading your data to Crashplan, you'll have to zip and encrypt it (as flabdablet said, using 7zip, not Zip encryption), but you won't have to deal with spreading it across multiple services and remembering to re-upload it. Crashplan monitors your folders and backs everything up. The multiple hard drives solution suggested by migurski sounds like more work than it's worth, and it's unclear whether it will save you any money. You have to keep buying Crashplan service, but if this is critical data then you will need to replace the hard drive regularly too - do you really trust a 5-year-old HD that's been sitting in a drawer? Plus, you can drop, lose, or format a hard drive. Crashplan cannot be dropped. You say you want a one-time backup. Okay, buy and install Crashplan, upload your documents, then uninstall the Crashplan client. Your files are still backed up and you can get them by reinstalling the client. Bonus: you could buy Crashplan's unlimited service and back up everything forever. So instead of a hack-y SkyDrive + Google Drive solution for just these files, you have all of your data backed up continuously. It sounds like you're serious about backups; why not use the best possible solution (considering it's $50/yr or less)?

I've been an http://rsync.net customer for years, both personally and for business. They're not the cheapest, but they're reliable and honest, and I don't hesitate at all recommending them. They'll be glad to help you get started no matter what kind of workflow or files you need to transfer; their support people are awesome.

Seconding crashplan, have been totally happy with their service thus far after we dumped mozy for them.

Re: expanding this into an ongoing solution, we're talking about 25 years of stuff. A great big lump of data which needs to be parked once and largely forgotten. My ongoing needs are met by Time Machine and DropBox. So I'm not looking for a backup regimen, I'm looking for a storage locker. Re: using a hard drive for offsite backup, I'm with Tehhund: "do you really trust a 5-year-old HD that's been sitting in a drawer?" In my case, though, it'd be more like 10 years. And since I can fit this data into free cloud storage (Google Drive + Skydrive), relative cost of different solutions isn't pertinent. Re: Crashplan, I trust Google or MS to probably (not definitely) be around in ten or twenty years. Crashplan, not so sure (same for RSync and Dolly Drive). Again, this is long term parking, not ongoing backup. And, again, the alternatives I have in mind are free. Re: 7Zip, cool, did not know about that. Thanks!

In that case, I'd probably consider a couple hard drives in a bank safe deposit box.