When sending files, S/FTP and managed file transfer (MFT) servers protect them with encryption. They use set methods to scramble the content. This keeps the files hidden from people without the correct key. The data stays unreadable until it reaches the right user.
Decryption changes the scrambled data back into a usable form. The person receiving the file must use a key. This key proves they are the right person to open the file. It is often shared or created during setup. Some keys are made when accounts are created. This process keeps data safe between systems. It is used in many online connections. SSL and TLS rely on it to protect data during transfer.
What is encryption?
Encryption turns readable data into a code. It uses an algorithm to swap the original text with random characters. The result is a file that no one can understand without the right key. The key must come from the same method that locked the file. Without it, the contents stay hidden. S/FTP and MFT servers rely on encryption to safely transmit files over the open internet.
Encryption is secure because the algorithm makes decryption by brute force guessing the encryption key so difficult that it becomes impossible using current computing power.
Encryption is useful because it:
- Ensures data privacy during transmission
- Prevents unauthorized access to files
- Protects sensitive metadata and session information, such as authentication credentials
Data encryption is required by a number of regulatory agencies, and it should be used at all practical times to maintain the confidentiality and integrity of your data throughout the transfer process.
Encryption methods
Encryption methods vary depending on the file transfer protocol employed (e.g., SFTP, FTPS, etc.) and the required level of security.
These methods generally fall into three categories:
- Private-key cryptography (also known as symmetric key encryption): Uses a single secret key to both encrypt and decrypt data
- Asymmetric key encryption: Uses public keys to encrypt and private keys to decrypt data
- Cryptographic hash functions: Used to augment the above encryption standards with another layer of security
Other common encryption methods are:
- AES (Advanced Encryption Standard)
- ChaCha20-Poly1305
- Diffie-Hellman
- RSA
- SHA-3
FTP and MFT server administrators can generally select multiple encryption options for their organization’s needs.
File transfer protocols that use encryption
Your file transfers should always be protected with encryption, and major protocols now encrypt transfers by default. These include:
- FTPES (explicit): Encrypts data by initiating an SSL/TLS connection after the FTP session starts
- FTPS (implicit): Uses SSL/TLS to encrypt the entire FTP session from the start
- HTTPS: Secures HTTP connections using SSL/TLS to encrypt data during transmission
- SFTP: Uses secure shell (SSH) to encrypt data and authenticate the connection
- TLS: Secures data with encryption between two systems
These encrypted protocols provide varying levels of security depending on the option used. Selecting the right protocol depends on your organization’s specific data protection and speed needs.
Types of decryption
Decryption methods vary by encryption type and system needs. Knowing the types helps match the right method to your organization’s security goals.
Common types of decryption include:
- Asymmetric key decryption: Uses a public key to encrypt and a private key to decrypt. It offers strong security but uses more computing power
- Client-side decryption: Happens on the user’s device after the data is received. It gives more control to the recipient
- Homomorphic decryption: Allows data to be used while still encrypted. It avoids exposing the raw data
- Hybrid decryption: Mixes symmetric and asymmetric methods. It balances speed with strong protection
- Symmetric key decryption: Uses one key for both encryption and decryption
Choose a method based on your organization’s system needs, speed limits and how much protection your data must have.
How to decrypt files
Decrypting a file can happen on its own or may need user action. This depends on the tool and type of encryption. The process usually follows these steps:
Integrity verification: The system looks at the file while it unlocks it. This makes sure nothing broke or changed during the transfer.
Authentication: You need to prove who you are before opening the file. This often means signing into your work system with a username and password.
Key validation: You must give the correct key to open the file. The key might be saved in your file program or handed to you by the organization. Most tools check the key by themselves.
File decryption FAQs
Decryption turns coded data back into its original form. It reverses the steps that scrambled the file. This lets you read or use the protected content.
A key or algorithm is needed to decrypt the file. The method depends on the kind of encryption used. Some systems use one key for both steps. Others use a different key to unlock the data. After decryption, the file works like normal.
Decrypting a file means converting encrypted data into a readable format using a decryption key or tool to restore the original content. This step allows approved users to access the information.
Yes, but only with the correct key. Encryption scrambles a file into unreadable text. It does this with a specific formula called an algorithm. This process also creates a key. That key is needed to unlock the data.
The key fits the scrambled data and makes it clear again. Guessing the key by brute force would take too long. Today’s computers cannot do it quickly. Without the key, the file stays locked. A strong encryption setup cannot be broken easily.
To open an encrypted file, you need the correct key or password. This key must be the same one used to lock the file. The same method must also be used to unlock it. A program that supports the encryption type is also required.
Some tools, like S/FTP or MFT servers, have built-in features for this. Others need separate decryption software. If the program supports it, decryption might start right away. You might also be asked to type in the key. If the key is right, the file will unlock. You will then be able to read or use it.
