> By [John L. Miller](https://www.quora.com/profile/John-L-Miller), Worked on several distributed and cloud storage services. PhD in distributed system. [Originally published](https://www.quora.com/Do-you-trust-the-cloud-to-securely-store-computer-files/answer/John-L-Miller) on [Quora](http://quora.com?ref=hackernoon).\n\nFiles stored in reliable cloud services are some of the most secure files you can have, provided you have good passwords. Google, Microsoft, and Amazon all provide reliable cloud services for consumer file storage.\n\nWhat makes them safe?\n\n* **Redundancy**. The service typically stores at LEAST three copies of each piece of data, all in different places. You need to have all three copies disappear at exactly the same moment (e.g. from three separate hard drive failures) to lose that data. After working on Exabyte-scale storage services, I have only seen this happen with a relatively small (e.g. 10^-9) fraction of data. And even that can usually be recovered, it just takes a couple days.\n* **Security**. Provided you take care of your credentials (e.g. your password), only you can access those files. They’re sitting on hard drives on machines in remote, physically secure data centers. Your connections to access that data are generally secured so that people can’t eavesdrop on it. The biggest danger is how you secure your local machine.\n* **Safe sharing**. If you want to give other people read access (or even allow them to write it), you can. No need to make a copy of the file, no need to mail them a thumb drive.\n\nPersonally speaking, my home machines have lost hundreds of gigabytes of data (video, audio, and some important stuff) to hard disk failures. I’ve NEVER lost ANY data I put in cloud services.\n\nThere are two provisos:\n\n1. If your password gets cracked, people can access that data if they have your password. Just like they could on your home machine.\n2. Viruses can still corrupt local copies of cloud data. If you have your computer set to automatically upload copies to the cloud, then you can overwrite the cloud copies with your corrupt copies. That’s not a problem with the cloud storage, it’s a problem with your machine.\n\nSome cloud storage has versioning of files to help you recover from accidental deletes and overwrites.\n\nOverall the cloud is a great place to securely store data.\n\n> By [John L. Miller](https://www.quora.com/profile/John-L-Miller), Worked on several distributed and cloud storage services. PhD in distributed system. [Originally published](https://www.quora.com/Do-you-trust-the-cloud-to-securely-store-computer-files/answer/John-L-Miller) on [Quora](http://quora.com?ref=hackernoon).\n\n> For more trending tech answers from [Quora](https://medium.com/@quoraanswers), visit [HackerNoon.com/quora](https://hackernoon.com/quora/home).