Concepts¶

It's better to know some basic concepts before using SCI.

Folders¶

The workflow of SCI:

flowchart LR
    subgraph "local filesystem (on PC 1)"
        A[source folder] -- SCI --> B[encrypted folder]
    end
    B <-- sync --> C[cloud drive]
    C[cloud drive] -- download --> D
    subgraph "local filesystem (on PC 2)"
        D[encrypted folder] -- SCI --> E[decrypted folder]
    end

Note

PC 1 and PC 2 are generally two different computers though they can be the same one (if you want to check whether SCI works correctly).

There are 4 folders in SCI.

Folder	Description
Source Folder	The folder you want to encrypt. SCI only reads this folder.
Encrypted Folder (PC 1)	The folder where the encrypted data is located. SCI incrementally updates this folder based on the Source Folder.
Encrypted Folder (PC 2)	This folder is just a copy of Encrypted Folder (PC 1) downloaded from the cloud drive. Strictly speaking, this folder should not be counted as a necessary part in SCI. Because in most cases, users will download some files instead of all the files in Encrypted Folder (PC 1). In such cases, this folder is just an ordinary download path of the cloud drive.
Decrypted Folder	The destination folder where the encrypted data is decrypted. It should be an empty folder before decryption.

User Password¶

There is a base password for the encryption of the source folder. It can be a simple hello or you birthday, while SCI will make the actual password strong enough.

Password Level¶

There are two types of password level:

Option 1	Option 2
Per file	Whole directory

1. Per file¶

Each file has its own password. The actual password is based on both the user password and the filename.

While this level is more secure, it adds to the difficulty of data recovery because of the extra filename.

2. Whole directory¶

Every file has the same password. The actual password is only based on the user password.

Database¶

A database has the following attributes:

Attribute	Description
Name	ID of a database
source folder	path to a source folder
encrypted folder	path to a encrypted folder
user password	see User Password
password level	see Password Level
encrypt scheme	tells SCI how the actual password is made. This is randomly made when users create a database

In all, a database contains all the information SCI needs to deal with the encryption and decryption of a source folder.

What SCI is not¶

A tool that follows every modern cryptography rule. Choose other tools that guarantee absolute data security if you prioritize it.
A cloud drive client.
A file-sync tool.

What's more?¶

See Detailed Encryption Mechanism.