Text encryption and decryption

Operating instructions for the text encryption and decryption tool

You can use this tool to encrypt and decrypt texts in a web interface. Here is a step-by-step guide:

Entering the text

Enter the desired text to be encrypted or decrypted in the text field labeled “Enter the text to be encrypted/decrypted”.

Selecting the encryption method

1. Select your desired method in the drop-down menu under “Select encryption method”:
   • AES (Advanced Encryption Standard): A secure encryption method.
   • Caesar-Encryption: A simple but less safe method.
2. If you select AES, another field will appear in which you can enter your secret key.

Entering the secret key (only for AES)

If you have selected the AES method, enter your secret key in the “Your secret key” field. The key must be at least 16 characters long.

Encrypting or decrypting the text

1. Click on “Encrypt” to encrypt the entered text.
2. Click on “Decrypt” to decrypt an encrypted text.

Interesting facts about encryption methods

Encryption methods are essential for the security of information in the digital space. Here are some important facts and differences that will give you a better overview of different encryption techniques:

Symmetric vs. asymmetric encryption

• Symmetric encryption: The same key is used for encryption and decryption. Security depends on the secrecy of this key. Symmetric algorithms are fast and require less computing power, making them ideal for large amounts of data and real-time applications.
• Asymmetric encryption: Uses two different keys – a public one for encryption and a private one for decryption. This is often used for secure communication and digital signatures, as the public key can be shared freely while the private one remains secure.

Important encryption algorithms

• AES (Advanced Encryption Standard): AES is the current standard for symmetric encryption. It offers strong security, especially in the variants AES-128, AES-192, and AES-256. AES is both secure and efficient and is used in applications such as VPNs, hard disk encryption and data transmission.
  RSA (Rivest-Shamir-Adleman): An asymmetric algorithm often used for secure key transmission. RSA is more computationally intensive due to the long key lengths, but is particularly secure.
  DES (Data Encryption Standard): DES was the standard for encryption in the 1970s, but is now considered insecure. DES has been replaced by 3DES, which executes the algorithm three times in succession and is therefore more secure.
  Caesar encryption: This simple symmetric encryption method is one of the oldest and shifts the letters in the text by a fixed number. It is easy to crack and is considered insecure, but is useful as an introduction to encryption concepts.

Modern techniques: Hashing and end-to-end encryption

• Hashing: In contrast to encryption, a hashing algorithm such as SHA-256 converts data into a fixed output that cannot be reversed. Hashing is used for password storage and data integrity, as even small changes in the input data completely change the hash.
• End-to-end encryption (E2EE): This method ensures that messages are only visible to the communication participants. Examples include messaging services such as WhatsApp and Signal, where the content remains encrypted throughout the entire transmission and even the service provider has no access.

The role of key length

The longer the key, the more secure the encryption, but also more resource-intensive. The key length is often measured in bits, with 128-bit and 256-bit being common standards today. As computers become more and more powerful, the recommended key lengths are also increasing.

Frequent attacks on encryption

• Brute force attack: An attacker systematically tests all possible keys. Long key lengths make this attack more difficult, as the time and computing power increase exponentially.
• Cryptanalysis: An attempt is made to exploit weaknesses in the encryption method. Modern algorithms such as AES are resistant to many of these techniques.
• Man-in-the-middle attack (MITM): With unprotected connections, an attacker can interpose himself between the sender and receiver, which poses a risk with insecure encryption methods.

Areas of application

Encryption protects in numerous applications such as:

• Banking and financial services: Sensitive information such as account data and transactions are encrypted.
• Cryptocurrencies: In blockchain technology, encryption is essential to secure transactions and ensure the integrity of the blockchain.
• Communication: In messaging apps to ensure user privacy.
• Storage of files and databases: To prevent unauthorized access to stored data.

Encryption is complex, but essential in our digitally networked world. The choice of the right method depends on the purpose of the application, the required security level and the technical requirements.