Secure? Hahahaha. It's only as secure as the S3 bucket it's in. Google 'AWS data leak'...
I purchased a lifetime cold storage when this company was called *sky something, they didn't last long. This company seems to have been around longer at least. * I think this is the same company as the website was nearly the same as the old "sky something" company I was with, they even had a deal to migrate your storage to this company (zoolz) had to pay of course, so my lifetime storage didn't help there. Pretty sure it was this : https://stacksocial.com/sales/skyhub-cloud-2tb-backup-lifetime-subscription-2 See here too : https://www.reddit.com/r/DataHoarder/comments/54zya0/skyhub_cloud_down/
Lifetime should mean lifetime. Otherwise we should be able to sue them for misleading information.
For those not sure about 'hot' and 'cold' storage, the guys over at CNET have provided this description, which was news to me and hopefully of help to others; In fact, your 1TB allotment consists of 500GB of "hot" (meaning instant, Dropbox-like) storage and 500GB of "cold" storage -- the kind you use as a semipermanent archive. (Note, however, that it can take several hours to retrieve files from cold storage.)