Every day, people send a huge amount of information over the internet.
This information can include passwords, messages, banking details, emails, personal files, and business data. Because much of this data is sensitive, it needs protection while it is stored or transmitted.
This is where encryption becomes important.
Encryption is a process that converts readable information into a protected format. Only someone with the correct method or key should be able to convert the protected data back into its original readable form.
For example, imagine sending a private message across the internet. Without protection, someone who gains unauthorized access to the data may be able to read it.
Encryption helps protect the information by transforming it into data that is not easily understandable without the appropriate decryption key.
As a result, encryption plays an important role in modern web applications, online banking, messaging apps, cloud storage, and many other digital systems.
In this article, we’ll explain what encryption is, how encryption works, the main types of encryption, and where encryption is used.
What Is Encryption?
Encryption is the process of converting readable data into an encoded or protected form using a mathematical algorithm and cryptographic key.
The original readable information is called:
Plaintext
The protected version is called:
Ciphertext
The basic process looks like this:
Plaintext → Encryption → Ciphertext
For example:
Hello
After encryption, the information may look completely different:
X7@kP!92...
The encrypted result is not meant to be understood directly.
To convert it back, an authorized system uses the appropriate decryption process and key.
The process then becomes:
Ciphertext → Decryption → Plaintext
Why Is Encryption Important?
Encryption helps protect information from unauthorized access.
Imagine sending sensitive data without encryption.
The process could look like this:
User
↓
Sensitive Data
↓
Internet
↓
Server
If an attacker gains unauthorized access somewhere along the path, the data may be exposed.
Encryption adds protection to the information.
The process becomes:
User
↓
Encrypt Data
↓
Encrypted Data
↓
Internet
↓
Server
↓
Decrypt Data
Therefore, even if encrypted data is intercepted, the attacker should not be able to understand it without the required cryptographic key.
How Does Encryption Work?
The basic encryption process can be understood in several steps.
Original Data → Encryption Algorithm → Encryption Key → Encrypted Data → Decryption Key → Original Data
Let’s look at each step.
Step 1: Original Data Exists
First, there is readable information.
For example:
Username: John
or:
Payment Information
This readable information is called plaintext.
Step 2: An Encryption Algorithm Processes the Data
An encryption algorithm applies mathematical operations to the plaintext.
However, the algorithm does not simply replace letters with random characters.
Modern encryption uses complex mathematical processes designed to protect the information.
The algorithm uses a cryptographic key as part of the encryption process.
Conceptually:
Plaintext
+
Encryption Algorithm
+
Encryption Key
↓
Ciphertext
Step 3: The Data Becomes Ciphertext
After encryption, the readable data becomes ciphertext.
For example:
Plaintext:
Hello
After encryption:
Ciphertext:
A9x#P2...
The exact output depends on the encryption algorithm, key, and other cryptographic parameters.
The important point is that the protected data should not be readable as the original information.
Step 4: The Encrypted Data Is Stored or Sent
Once the information is encrypted, it can be transmitted or stored.
For example:
Application
↓
Encrypt Data
↓
Encrypted Data
↓
Internet or Storage
The encrypted information remains protected while it is in that encrypted form.
Step 5: The Authorized System Decrypts the Data
When an authorized person or system needs to use the information, it decrypts the ciphertext using the appropriate key.
Conceptually:
Ciphertext
↓
Decryption Key
↓
Decryption Process
↓
Plaintext
The original readable data can then be recovered.
A Simple Encryption Example
Imagine that Alice wants to send a private message to Bob.
The original message is:
Hello Bob
The message is encrypted before it is sent:
Hello Bob
↓
Encryption
↓
Encrypted Message
The encrypted message travels across the network:
Alice
↓
Encrypted Message
↓
Internet
↓
Bob
Bob then uses the appropriate decryption method to read the original message.
Therefore, encryption helps protect the information while it is being transmitted.
What Is an Encryption Key?
An encryption key is a value used by an encryption system to transform data.
Keys are a critical part of modern cryptography.
The process can be simplified as:
Plaintext
+
Key
↓
Encryption
↓
Ciphertext
A key is also involved when data needs to be decrypted.
Depending on the type of encryption, the same key or a different related key may be used.
The Two Main Types of Encryption
There are two major categories of encryption:
- Symmetric encryption
- Asymmetric encryption
Both protect information, but they use keys differently.
What Is Symmetric Encryption?
Symmetric encryption uses the same secret key for encryption and decryption.
The process looks like this:
Original Data
↓
Encrypt with Secret Key
↓
Encrypted Data
↓
Decrypt with Same Secret Key
↓
Original Data
For example:
Key A
↓
Encrypt
↓
Encrypted Data
↓
Decrypt
↓
Key A
The same secret key is used for both operations.
Advantages of Symmetric Encryption
Symmetric encryption is generally efficient and suitable for encrypting large amounts of data.
It is commonly used when systems need to protect data quickly.
For example, it can be used to protect:
- Files
- Database data
- Application data
- Network traffic
However, the secret key must be protected carefully.
If an unauthorized person obtains the key, they may be able to decrypt data protected with that key.
What Is Asymmetric Encryption?
Asymmetric encryption uses two related keys:
- Public key
- Private key
These keys have different purposes.
The public key can be shared.
The private key must remain secret.
A simplified example looks like this:
Public Key
↓
Encrypt
↓
Ciphertext
↓
Private Key
↓
Decrypt
↓
Original Data
Asymmetric cryptography is also used for other important security functions, including digital signatures and secure key exchange.
Public Key and Private Key Explained
Imagine a secure mailbox.
Anyone can put a message into the mailbox.
However, only the person with the correct key can open it.
Conceptually:
Public Key → Used to Protect Data
Private Key → Used to Access Protected Data
The public key can be distributed to other people.
The private key must remain protected.
This approach helps solve the problem of securely establishing communication between systems.
Symmetric vs Asymmetric Encryption
| Feature | Symmetric Encryption | Asymmetric Encryption |
|---|---|---|
| Number of keys | One shared secret key | Two related keys |
| Encryption speed | Generally faster | Generally slower |
| Best suited for | Encrypting larger amounts of data | Key exchange and cryptographic identity use cases |
| Key sharing | Requires secure handling of the shared key | Public key can be shared |
| Common role | Data encryption | Secure communication and key exchange |
Modern security systems often use both approaches together.
How Encryption Works on Websites
Encryption is an important part of secure web communication.
For example, when you visit a website using HTTPS:
https://example.com
your browser and the server use cryptographic protocols to establish a protected connection.
Conceptually:
Browser
↓
Secure Connection Setup
↓
Server
↓
Protected Data Exchange
This helps protect information transmitted between the browser and the website.
For example:
Browser
↓
Encrypted Request
↓
Server
Server
↓
Encrypted Response
↓
Browser
HTTPS uses TLS to provide encryption and additional security properties for data in transit.
Encryption in HTTPS
Suppose you enter a password on a website.
Without a secure encrypted connection, sensitive information could be at greater risk of exposure.
With HTTPS, the browser and server establish a secure communication channel.
The process is more complex than simply encrypting every message with a public key.
In practice, modern TLS protocols use cryptographic techniques to authenticate the server and establish shared secrets, after which efficient symmetric encryption is generally used to protect application data.
This combination provides both security and performance.
Where Is Encryption Used?
Encryption is used in many technologies.
1. Websites and HTTPS
Encryption helps protect data exchanged between browsers and web servers.
For example:
Browser
↓
Encrypted Communication
↓
Website Server
2. Messaging Applications
Messaging applications may use encryption to protect conversations.
Depending on the application’s design, messages can be encrypted during transmission and, in some systems, protected with end-to-end encryption.
3. Online Banking
Banks and financial services use encryption to help protect sensitive information.
This can include:
- Login information
- Payment details
- Account data
- Transaction information
4. Cloud Storage
Cloud services can use encryption to protect stored files and data.
Encryption may be applied while data is being transmitted, while it is stored, or both.
5. Mobile Applications
Mobile applications can use encryption to protect sensitive information and network communication.
For example:
Mobile App
↓
Encrypted Request
↓
API Server
6. Password Management
Encryption can also be part of password management systems.
However, it is important to understand that passwords are often protected using password hashing, which is different from ordinary reversible encryption.
This distinction is important because hashing is designed to be one-way, while encryption is designed to allow authorized decryption.
Encryption vs Hashing
Encryption and hashing are different concepts.
Encryption
Encryption is reversible when the authorized party has the correct key.
Plaintext
↓
Encryption
↓
Ciphertext
↓
Decryption
↓
Plaintext
Hashing
Hashing is designed to be one-way.
Original Data
↓
Hash Function
↓
Hash Value
A secure password system generally verifies a password by hashing the entered password and comparing it appropriately rather than decrypting the stored password.
Therefore:
Encryption protects data that may need to be recovered.
Hashing is used for one-way verification and integrity-related purposes.
Encryption vs Encoding
Encryption and encoding are also different.
Encoding changes data into another format for compatibility or transmission.
For example, encoding may make data easier for a system to process.
However, encoding is not designed to provide security.
Encryption is specifically designed to protect information from unauthorized access.
Therefore:
Encoding ≠ Encryption
Anyone with the correct encoding method can usually decode encoded data.
Encryption, by contrast, depends on cryptographic security and appropriate key management.
Encryption at Rest and Encryption in Transit
Encryption is often discussed in two common situations.
Encryption in Transit
This protects data while it moves between systems.
For example:
Browser
↓
Encrypted Connection
↓
Server
HTTPS is a common example.
Encryption at Rest
This protects data while it is stored.
For example:
Database
↓
Encrypted Stored Data
or:
File
↓
Encrypted File
Many systems use both approaches.
As a result, data can receive protection while it is being transmitted and while it is stored.
Is Encrypted Data Completely Safe?
Encryption is a powerful security tool, but it does not solve every security problem.
Security depends on several factors, including:
- The encryption algorithm
- Key strength
- Key management
- Software implementation
- Server security
- User security
- Application vulnerabilities
For example, strong encryption may not protect data if an attacker gains access to an unprotected decryption key.
Similarly, encryption cannot automatically protect an application from every security vulnerability.
Therefore, encryption should be part of a broader security strategy.
Why Is Key Management Important?
An encryption system is only as secure as the way its keys are managed.
Imagine storing encrypted data in one location and the decryption key openly beside it.
The encryption would provide little practical protection.
A secure system should carefully manage:
- Where keys are stored
- Who can access keys
- How keys are rotated
- How keys are backed up
- How compromised keys are replaced
Therefore, key management is one of the most important parts of cryptographic security.
Common Encryption Algorithms
Modern systems use well-established cryptographic algorithms rather than creating custom encryption methods.
Examples include:
- AES for symmetric encryption
- RSA for asymmetric cryptography in appropriate use cases
- Elliptic-curve cryptography for various modern public-key operations
The correct algorithm and configuration depend on the security requirement.
Developers should avoid creating their own encryption algorithms.
Instead, applications should use well-reviewed cryptographic libraries and established security standards.
Best Practices for Using Encryption
Developers and organizations should follow several important practices.
1. Use Established Cryptographic Standards
Do not create your own encryption algorithm.
Use trusted and widely reviewed cryptographic systems.
2. Protect Encryption Keys
Keys should be stored and managed securely.
3. Use HTTPS
Web applications should protect sensitive communication with HTTPS.
4. Keep Security Libraries Updated
Cryptographic software and dependencies should be kept up to date.
5. Avoid Hardcoding Secrets
Private keys and sensitive secrets should not be directly placed in publicly accessible source code.
6. Encrypt Sensitive Data When Appropriate
The type of protection should match the sensitivity and purpose of the data.
7. Use Encryption With Other Security Measures
Encryption should work alongside:
- Authentication
- Authorization
- Access control
- Secure coding
- Input validation
- Security monitoring
A strong security system uses multiple layers of protection.
A Simple Encryption Flow
The complete process can be summarized like this:
Step 1: Original Data
Hello
Step 2: Encryption
Hello
+
Encryption Key
↓
Encryption Algorithm
Step 3: Encrypted Data
X8@kL2...
Step 4: Secure Storage or Transmission
Encrypted Data
↓
Internet or Storage
Step 5: Decryption
Encrypted Data
+
Correct Key
↓
Decryption
↓
Hello
The complete flow is:
Plaintext → Encryption → Ciphertext → Storage or Transmission → Decryption → Plaintext
Final Thoughts: How Does Encryption Work?
Encryption protects information by converting readable data into a protected form called ciphertext.
The encryption process uses mathematical algorithms and cryptographic keys.
Authorized systems can use the appropriate decryption process to recover the original data.
Modern applications use encryption in many areas, including websites, messaging systems, cloud storage, financial services, and mobile applications.
The basic idea is simple:
Readable Data → Encrypt → Protected Data → Decrypt → Readable Data
However, real-world encryption systems depend heavily on correct algorithms, secure implementation, and proper key management.
Conclusion
Encryption is one of the most important technologies used to protect digital information.
It helps secure data while it is transmitted and while it is stored.
From HTTPS websites to online banking and cloud storage, encryption is a fundamental part of modern cybersecurity.
Understanding the difference between plaintext, ciphertext, encryption keys, symmetric encryption, and asymmetric encryption makes it easier to understand how modern systems protect sensitive information.
The most important thing to remember is that encryption is not just about hiding data.
It is about using trusted cryptographic methods and secure key management to protect information from unauthorized access.
