Compressing all your files to a single archive and storing it in the cloud ( such as DropBox, Amazon S3, SkyDrive, Dropsend, Box.net ) has several advantages and disadvantages, one of the most disadvantages is that the data in the cloud is more dangerous and crackable, it can be stolen by the bad employees or hackers, if it’s not well encrypted, someday you might wish that you have never uploaded it to the cloud.
If you want to assure that your files in the cloud is intact and can not be decrypted, just follow the steps in the following sections.
1, Compress and encrypt your data with 7Zip or WinRAR
7Zip is an open source file archiver that allows to compress and encrypt files with ease, the encryption method used by 7Zip is AES-256. Alternatively, you can use WinRAR to achieve the same effect.
2, Put the compressed archive in a virtual disk created with TrueCrypt
After you’ve compressed your documents into a sole file, you can add an extra protection to it by moving it into an encrypted disk produced with TrueCrypt or similar disk encryption tools.
3, Split the file into 2 parts
Now your files should be secure enough, however, if you do not believe that 7Zip or TrueCrypt is reliable, you can do more if you want. Splitting the archive into several parts and uploading them to different websites does make sense.
Alternatively, you can cut the header of the file and save it to a new file, or fill in the header with random bytes instead of removing it. Because the file is usually very large, it’s almost impossible to open and edit it with ordinary text editors such as UltraEdit and NotePad++, in such cases, text editors optimized for large files come in handy, Hxd(review ) is the most excellent one among them.
4, Save your password in another place
After you’ve splitted the archive into multiple separate files, you can upload them to different online storages, and save your passwords to another location. Now no one could decrypt your files.
But care should be taken when you save your passwords, it’s not recommended to save them with online password managers like LastPass, the offline password managers is more reliable than the online ones, for example, keepass. And you should not login and transfer your passwords with HTTP connections or FTP connections, the reason will be mentioned in the next article.
5, Verify your data periodically
Before the final files are uploaded to the cloud, you should decrypt and extract them to your hard drive and verify the integrity of them, you could perform this task easily with MD5Summer, a portable and easy using utility which has been used by me for many years.
Finally, you can verify the integrity of the files in the cloud with the unique fingerprints of them, for instance, the MD5 checksum or SHA checksum.
If you have any other good ideas, please leave a comment below.