In today’s world of big data and cloud computing, data is everywhere. And data is power. This attracts all kinds of malicious users and attackers who try to steal sensitive data.
According to IBM’s Cost of Breach Report, the average cost for a data breach as of 2020 is about 3.86 Million. According to SlickText, more than 5 billion people send and receive texts and files over the internet every day!
If these messages were to be sent and received with no protection, any high-school student can intercept and read the messages with the right easily available software.
That is why most chat applications, file transfer software and other web applications almost always use end to end encryption (E2EE).
But it is always safer to add another layer of security than built-in encryption provided by the platform used for the transfer. So, these questions are common nowadays:
- How do you encrypt a message?
- What are the different ways you can do it?
- How can you decrypt an encrypted message that was intended for you?
Lucky for you, we will address these questions today, in this article.
Message Encryption Methods
Private Key Encryption
Private Key Cryptography or Symmetric-Key Algorithms are one of 2 major classifications of cryptographic encryption. The key idea is to use a secret keyword to encrypt the plaintext to cypher-text.
The same secret keyword is used to decrypt the cypher-text back to the plain-text. So for example, let us say the sender encrypts a message with ‘tiger’ as the private key.
He then has to find a way to deliver the private key securely to the receiver for him to be able to decrypt it.
Key Advantage: Simple, direct and easy to use
Key Disadvantage: Securely delivering the key could be tricky.
Some popular private key encryption algorithms are Blowfish, DES (Data Encryption Standard), AES (Advanced Encryption Standard) and Twofish. Note that these algorithms diﬀer only in the mathematical functions used to generate the cipher-text.
How to use them to encrypt messages?
The above popular encryption algorithms work based on some one-ay mathematical functions. There are tons of free-ware on the internet that can encrypt messages and files based on the selected algorithm. It is as simple as:
- Upload a file or Enter the String.
- Enter the secret key.
- Obtain the encrypted cipher-text.
Public Key Encryption
Public Key Encryption or Asymmetric Key Algorithm is the other major method to encrypt files. The idea here is to use 2 keys. First, a public key that can be shared with anyone.
Second, a private key that is only known to the owner.
The sender encrypts the message with the receivers public key and the receiver will be able to decrypt it with the corresponding private key.
Key Advantage: Solves the problem of having to securely deliver the secret key.
- The keys have to be generated and cannot be created randomly.
- Increases complexity and decreases ease of use.
Some famous public-key algorithms are RSA (Rivest-Shamir-Adlemen), ECC (Elliptical Curve Cryptography) and DSS (Digital Signature Standard).
How to use them to encrypt messages?
Some free online tools and applications let you encrypt messages with these algorithms. The process is pretty simple
- Choose Algorithm to be used.
- Generate Public/Private key pair.
- Input the Plain-text that is to be encrypted.
- Process and Output the Cipher-text.
A great tool to encrypt messages with RSA online is DevGlan.
How to read encrypted messages?
Sensitive data is usually encrypted by senders. Most chat applications and file transfer platforms automatically encrypt and decrypt the messages/files based on device IDs.
But in the case that you have an encrypted message in your hands, the only way to decrypt it is by using a decryption key.
In Private Key Cryptography
- You need the same private key that was used to encrypt the message from the sender. You would also need to know the algorithm that was used to encrypt the message. These details must come from the sender himself/ herself.
- Use an encryption/decryption tool, enter the algorithm used, the secret key and the cypher. If the secret key is correct, you will get the decrypted plain text
In Public Key Cryptography
Here you, the receiver, do not need additional sensitive information (the secret key) from the sender except for the cipher-text itself. Note that here the message is encrypted with YOUR public key.
- Use an encryption/decryption tool, enter your private key, the algorithm and the cipher-text. If the text was encrypted with YOUR public key, you will have the correct decrypted message.
How to read encrypted message without decrypting?
It is simply impossible to decrypt a message without knowing the appropriate key and the algorithm. The most direct way to attempt to read a cipher-text without disrupting is via a brute-force attack.
A brute-force attack is an attempt to guess the correct key by trying a large number of random guesses. Brute force attack of the latest algorithms is beyond the scope of the current state of the art computing power.
Moreover, it is unethical and illegal to attempt to read unauthorized messages and data.
A few popular encryption/decryption tools
- Terminal (Mac and Linux) – OpenSSL comes built-in with macOS Catalina and other previous versions. With the OpenSSL terminal command, keys can be generated and various encryption and decryption tasks carried out. The general command syntax is : $ openssl command [ command_options ] [ command_arguments ]
2. Encrypto – Is a free-ware on the App Store the encrypts files with AES-256.
- AxCrypt – Is a cross-platform compatible tool that allows encryption with diﬀerent algorithms. It has a premium subscription for cloud storage and key-sharing features.
Frequently Asked Questions (FAQs)
How to encrypt text messages?
Text files and text messages are not very diﬀerent. All files ultimately are only a set of characters that are readable with the correct software. Almost all kinds of files can be encrypted.
Some encryption tools like the ones mentioned above will be able to carry out string encryption in-line.
How to remove encryption from text messages?
By decrypting them. You can remove the encryption of the messages with the correct secret key and knowing the algorithm used for encryption.
What is PGP encryption?
Pretty Good Privacy (PGP) is an encryption software program that is used popularly encrypt files and emails. It was introduced in 1991 and became popular as a free-ware. It adds a layer of security to sensitive emails. It uses a combination of both public-key cryptography and private-key cryptography. Additionally, data is also compressed and hashed serially. It follows the OpenPGP encryption standard.
In addition to this, PGP verifies that the information was not tampered with, using digital signatures. Guarantees non-repudiation of data.
How to use PGP encryption?
Similar to other symmetric and asymmetric key cryptographic algorithms, PGP encryption free-ware is available via multiple tools. It is available across all OSs. GPG Suite and GNU PG are a couple of tools available for Mac and Windows respectively. They allow the creation, modification and deletion of OpenPGP keys. The working is pretty direct
- Create PGP Public and Private Keys
- PGP then creates a session key based on keystrokes and mouse movement
- The session key with an existing fast encryption algorithm encrypts the data into ciphertext
- Once encrypted the session key is encrypted by the recipient’s public key. This is sent along with the ciphertext to the recipient.
- Receiver’s private key is used to decrypt the session key and thus, decrypt the ciphertext.
An engineer and a tech enthusiast, driven by curiosity.