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Martin Goellnitz edited this page May 8, 2023 · 13 revisions

JFileSync3

JFileSync3

[S]ecure It - Save [R]esources - [H]ave it with you

File Syncing, Encryption, Compression for the cloud.

Latest Release

JFileSync3 wants to be a part in your puzzle to keep your confidential data secret while providing means to access it in the cloud, do regular backups, stay in sync with several - also mobile - devices, and be able to share parts of this data with others.

The Backup Story

[S] [R]

Your confidential data of every day usage - so the files that are changing a lot - are the most relevant to have a recent backup for. So it is a good idea to do backups very often to lose as little as possible data in case something happens.

If you consider your backup target - cloud based or local media - untrusted (which is a good idea anyway since you might loose media and cloud as inheritently insecure), those backups should be encrypted.

JFileSync3 helps you solve this issues through profiles where you syncronize pairs of folders where one of the is the encrypted copy of the other. This encrypted copy may reside on backup media or on a local folder which in turn is synced through the network to you cloud based story.

It does, however, not keep several versions of the sames files and files to be able to recover earlier revisions. So, it only helps you recover you latest working state of the files.

Also JFileSync3 supports to leave out the local, encrypted copy and directly syncronize with a WebDAV backend in the cloud.

The Allways Available Story

[S] [H]

The downside of encryted data in the cloud or on your local backup devices is, that you cannot easily access them from you mobile devices or share them with others.

If you need to have your files available while on the go, you will definetely want to sync them to you mobile devices.

The only encrypted filesystem I found pracitcable and available for Windows, Linux, iOS, and Android is EncFS. This might change over time, but at the time of writing (Mid 2023), this is still the case.

JFileSync3 supports the synchronization of pairs of folders where one copy is an EncFS encrypted folder. As opposed to mounting EncFS folders with encfs4win, or encfs for Linux this provides an instance of your data locally accessible in unencrypted state.

The Resource Saving Story

[R]

Resource usage saving with JFileSync3 has been integrated with the encryption part: To increae entropy and reduce known plain text, JFileSync3 (except for EncFS folders) compresses data before encryption. If certain file size limits are not exceeded and JFileSync3 doesn't have to assume, that the data is already compressed - like for archive files, three compression methods are tried in parallel and the result of the one with the smallest compression result is stored.

This is time consuming but saves storage resources and transfer resources. It - of course - invests your local computing resources.

The compression methods tried are LZMA, bzip2, and RFC1951.

[R]

as you see, JFileSync3 doesn't do online syncing of pairs of folders like many other services do. JFileSync3 is intended to be used in cooperation with some of those services.

To be able to use as many backends as possible - e.g. for sharing and cooperation with others, using some of those services, you will discover, using too many of them at a time a rather bad idea. Having installed more the say two online syncing services slows down local operation and file changes and file change discovery on your local machine.

If there are important files not changing that often, you can decide to check changes to these files not that often, and not let JFileSync3 do the syncing at any time, but at points in time of your choice.

This again saves bandwidth and in this case local CPU cycles.

If you use this feature together with the WebDAV backends of some of the online synching services like e.g. Yandex, you can decide to use online syncing for these directories on one machine at use "offline" syncing with JFileSync3 on other machines. Of course this can also be used for sharing, where you sync files with JFileSync3 via WebDAV while your sharing partner gets your changes immediately via online syncing.

List of Storage Services

During the course of setting up and maintaining a reasonable backup, security, and mobile access scenario for me and some other people, I came across numerous storage services and now collected some [notes on them](SyncingServices. You might find them helpful.

Besides JFileSync3

Why?

The history of my cloud based backup, encryption, and sharing setup (german) Etwas wolkige Sicherheit