Encoding vs Hashing vs Encrypting vs Obfuscation

Hi all, i wanna share my little experience. I’m still working with ionic.

Now, i learn about data security in mobile application. I learn from the very basic, and it drives me into data encryption. I build a little application to explore. The condition is : this application will work offline and online. When it works offline, the data will saved on the phone storage (local). This can be done by using sqlite (for example). And, the data is so important so we want to protect.

As the authentication i just use basic auth, nice artikel is here https://luckymarmot.com/paw/doc/auth/basic-auth and i still learning to use JWT (JSON Web Token) for authentication, login credentials etc. Next time, i’ll share. Now, i wanna talk about encode, hash and encrypt. I’ve read some article and i’ll share it with you.

Encoding

The purpose of encoding is to transform data so that it can be properly (and safely) consumed by a different type of system, e.g. binary data being sent over email, or viewing special characters on a web page. The goal is not to keep information secret, but rather to ensure that it’s able to be properly consumed.

Encoding transforms data into another format using a scheme that is publicly available so that it can easily be reversed. It does not require a key as the only thing required to decode it is the algorithm that was used to encode it.

Examples: ASCII, Unicode, URL Encoding, Base64

(source)

Hashing

Hashing is a type of algorithm which takes any size of data and turns it into a fixed-length of data.  Hashing is a one way function. It’s irreversible, you apply the secure hash algorithm and you cannot get the original string back.

Some hashing algorithms:

  • MD-5
  • SHA-1
  • SHA-2
  • SHA-3

When to use hash? 

We can use it to store password, as hashes are inherently one-way in their nature. By storing passwords in hash format, it’s very difficult for someone with access to the raw data to reverse it (assuming a strong hashing algorithm and appropriate salt has been used to generate it). 

When storing a password, hash it with a salt, and then with any future login attempts, hash the password the user enters and compare it with the stored hash. If the two match up, then it’s virtually certain that the user entering the password entered the right one.

Encrypting

Encryption turns data into a series of unreadable characters, that aren’t of a fixed length. The key difference between encryption and hashing is that encrypted strings can be reversed back into their original decrypted form if you have the right key. 

There are two primary types of encryption, symmetric key encryption and public key encryption. In symmetric key encryption, the key to both encrypt and decrypt is exactly the same. This is what most people think of when they think of encryption. 

Public key encryption by comparison has two different keys, one used to encrypt the string (the public key) and one used to decrypt it (the private key). The public key is is made available for anyone to use to encrypt messages, however only the intended recipient has access to the private key, and therefore the ability to decrypt messages.

Popular algorithm : 

  • AES – AES is the “gold standard” when it comes to symmetric key encryption, and is recommended for most use cases, with a key size of 256 bits.
  • PGP – PGP is the most popular public key encryption algorithm
  • RSA
  • DES

When should be used?

The purpose of encryption is to transform data in order to keep it secret from others, e.g. sending someone a secret letter that only they should be able to read, or securely sending a password over the Internet. Rather than focusing on usability, the goal is to ensure the data cannot be consumed by anyone other than the intended recipient(s).

If you have a usecase where you have determined that encryption is necessary, you then need to choose between symmetric and public key encryption. Symmetric encryption provides improved performance, and is simpler to use, however the key needs to be known by both the person/software/system encrypting and decrypting data.

If you were communicating with someone on the other side of the world, you’d need to find a secure way to send them the key before sharing your secure messages. If you already had a secure way to send someone an encryption key, then it stands to reason you would send your secure messages via that channel too, rather than using symmetric encryption in the first place. 

Obfuscation
obfuscated

The purpose of obfuscation is to make something harder to understand, usually for the purposes of making it more difficult to attack or to copy. One common use is the the obfuscation of source code so that it’s harder to replicate a given product if it is reverse engineered.

It’s important to note that obfuscation is not a strong control (like properly employed encryption) but rather an obstacle. It, like encoding, can often be reversed by using the same technique that obfuscated it. Other times it is simply a manual process that takes time to work through.

Another key thing to realize about obfuscation is that there is a limitation to how obscure the code can become, depending on the content being obscured. If you are obscuring computer code, for example, the limitation is that the result must still be consumable by the computer or else the application will cease to function.(source)

Summary

  • Encoding is for maintaining data usability and can be reversed by employing the same algorithm that encoded the content, i.e. no key is used.
  • Encryption is for maintaining data confidentiality and requires the use of a key (kept secret) in order to return to plaintext.
  • Hashing is for validating the integrity of content by detecting all modification thereof via obvious changes to the hash output.
  • Obfuscation is used to prevent people from understanding the meaning of something, and is often used with computer code to help prevent successful reverse engineering and/or theft of a product’s functionality. (source)
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