Hashing vs Encryption vs Encoding: Let's Learn the Differences

In today’s digital world, protecting data is more important than ever. Over 90% of websites rely on hashing, not encryption, to store passwords securely. But what’s the difference between hashing, encryption, and encoding? Let’s break down these concepts in simple terms, and explore where and why they are used.

What Is Hashing?

Hashing is like taking some text—say, “hello”—feeding it into a “magic blender,” and getting out a short, fixed-length code like 2cf24d…—a hash. Every time “hello” goes in, you always get the same hash. But if you tweak “hello” to “Hello” (capital H), you get a totally different code. Hashing is one-way—you can’t “unblend” the hash to get “hello” back.

Example:

• You type “apple” into a hash function → you get 1f3870be274f…
• Try again with “apple” → same result.
• Try “apple “ (with a space) → a completely different result, like 5a105e8b9d40…

Why is this useful?
It lets systems check your password without ever storing the actual password — they store the hash and compare the hash of what you type to the stored one.

 

What Is Encryption?

Encryption is like locking a message in a box and giving someone the key so they can open it. You take plain text—"hello"—and turn it into coded text—like Xz7!G2—that looks meaningless without the key. But someone with the key can decrypt it and get "hello" back. Encryption is two-way.

Example for students:

• Original message: “help me.”
• Encrypt it (with a secret key) → “D8s!Qp”
• With the correct key, you can decrypt “D8s!Qp” back to “help me.”

Why this matters:
You use encryption when you need to hide something temporarily, but still be able to read it later—as with secret messages or safely sending emails.

 

Simple Comparison: Hashing vs Encryption

Feature	Hashing	Encryption
Reversible?	No (one-way)	Yes (two-way with a key)
Typical Use	Checking data integrity, passwords	Confidential messaging, data storage
Output Size	Fixed length (regardless of input size)	Variable length (depends on input and method)
Key Needed to Reverse?	No key, and you cannot reverse	Yes, correct key required to decrypt

 

Now Add Encoding: What Is That?

Encoding is like translating a message into another format, e.g. “hello” → “aGVsbG8=" (that’s Base64). Anyone can decode it easily. Encoding isn’t for security—it’s for compatibility (making data work across systems).

Why show it together?
People often confuse encoding, hashing, and encryption—so here's a quick breakdown:

• Encoding: reversible, no secret. Used to format data (like Base64).
• Hashing: not reversible, no secret. Used to compare data securely.
• Encryption: reversible, secret key required. Used to protect data confidentiality.

 

 “Hashing vs Encryption vs Encoding” — Use Cases & Example 

Hashing

• Passwords: When you log in, your password is hashed and compared to the stored hash—server never stores actual password.
• File integrity: You download a file and check its hash (like SHA‑256) to ensure it hasn’t been tampered with.
• Digital fingerprinting: Unique ID for data, even tiny changes produce completely different hash.

Example: Simple Mathematical Hashing of "hello"

Let’s use a very basic hash function for educational purposes:

$$\text{Hash}("string") = \sum_{i=1}^{n} (\text{ASCII}(char_i) \times i)$$

Where:

• ASCII(char_i) is the ASCII value of the character at position $i$

• $i$ is the position (starting at 1)

Step-by-step: Hashing "hello"

The string is:

h   e   l   l   o
1   2   3   4   5   ← Positions

ASCII values:

• 'h' = 104

• 'e' = 101

• 'l' = 108

• 'l' = 108

• 'o' = 111

Now apply the formula:

$$\text{Hash}("hello") = (104×1) + (101×2) + (108×3) + (108×4) + (111×5)$$ $$= 104 + 202 + 324 + 432 + 555$$ $$= \boxed{1617}$$

So, the hash value of "hello" using our simple function is 1617.

Note:

Real hash functions like SHA-256 or MD5 are much more complex, designed for cryptographic strength and resistance to collisions. But this example helps you understand the concept mathematically.

Encryption

• Secure messages: Chat apps encrypt messages so only the recipient can read them.
• Secure websites (HTTPS): Websites encrypt data between your browser and server.
• Data at rest: Sensitive files are encrypted so only authorized users can open them.

Let’s use a simple Caesar Cipher (a form of substitution cipher) for math demonstration.

Caesar Cipher with shift = 3

Each letter is shifted +3 positions in the alphabet.

Original string: "hello"

Positions in alphabet:

• h = 8

• e = 5

• l = 12

• l = 12

• o = 15

Now shift each by +3:

$$\text{Encrypted}("hello") = (h+3, e+3, l+3, l+3, o+3) = (11, 8, 15, 15, 18) = (k, h, o, o, r)$$

$$\text{ Encrypted}("hello")=(h+3,e+3,l+3,l+3,o+3)=(11,8,15,15,18)=(k,h,o,o,r)$$

So:

$$\text{Encrypted("hello")} = \boxed{"khoor"}$$

You can decrypt this by shifting letters back by -3.

Encoding

• Email attachments: Binary files are encoded (e.g., Base64) so they can be safely sent as text.
• URLs: Spaces and special characters are percent-encoded for safe web transmission.
• Data migration: Encode data into safe formats for systems that can’t handle raw bytes.

Let’s use Base64 Encoding for "hello"

ASCII of "hello" is:

• h = 104 → 01101000

• e = 101 → 01100101

• l = 108 → 01101100

• l = 108 → 01101100

• o = 111 → 01101111

Full binary string:

01101000 01100101 01101100 01101100 01101111

Group into 6 bits:

011010 000110 010101 101100 011011 000110 1111

Pad the last group to 6 bits:

011010 000110 010101 101100 011011 000110 111100

Now map each 6-bit group to Base64 table:

6-bit binary	Decimal	Base64
011010	26	a
000110	6	G
010101	21	V
101100	44	s
011011	27	b
000110	6	G
111100	60	8

So:

$$\text{Base64("hello")} = \boxed{"aGVsbG8="}$$

You can decode Base64 back to "hello" easily.

Let's understand "hello" example in a tabular form with hashing, encryption and encoding. 

Operation	Output	Reversible?	Secure?	Use Case
Hashing	1617	No	Yes	Password storage, checksums
Encryption	"khoor"	Yes	Yes	Messaging, secure data
Encoding	"aGVsbG8="	Yes	No	Data transport, file formats

 

 “Hashing vs Encryption” Detailed Comparison with Examples

A layman’s analogy:

• Hashing: Imagine turning your homework paper into a fingerprint image—you can’t turn the fingerprint back into your paper, but you can later compare fingerprints to verify it's the same.
• Encryption: Put your homework in a locked safe. With the key, you or your teacher can open it later.

For advanced learners:

• Hashing uses one-way mathematical functions (like SHA‑256, Argon2, bcrypt) that transform input into a fixed-length digest. A small change in input causes a large change in output (avalanche effect).
• Encryption uses symmetric (e.g., AES) or asymmetric (e.g., RSA) algorithms—data is transformed to ciphertext using keys, and only reversible with the right key(s).

Example:

• Hash “password123” using SHA‑256 → ef92b778...
• Encrypt “password123” with AES key → something like JHJg9#12…
• If someone steals the hash, they can’t get the password.
• If someone steals the encrypted string but not the key, they can’t decrypt it.

 

Password Hashing vs Encryption

Let’s dive into how these differ and why hashing is preferred for passwords:

Password Hashing

• The system stores Hash(password + salt) (salt: random extra text).
• You enter your password → system adds the same salt and hashes again → compares to stored hash.
• Advantages:
• Even if someone steals the database, they only get hashes—not passwords.
• With salt, identical passwords don’t produce identical hashes, making theft harder.

Password Encryption (not recommended)

• System encrypts password with a key and stores it.
• To verify, system decrypts and compares the original password.
• Problems:
• If someone steals the key, they can decrypt all passwords.
• This is insecure—typically avoided for password storage.

Example:

• Safe practice: Store hash = Hash("MyPassword" + randomSalt).
• Bad practice: Store encrypt("MyPassword", key) → risky if key is exposed.

Advanced Examples for Deep Learners

Hashing Attack Example

If a website stores Hash("password") as 5e8848..., an attacker could use rainbow tables—precomputed tables of hash outputs—for common words. To combat that:

• Add salt: Hash("password" + "random123") → even “password” gets a unique hash.
• Use slow algorithms like bcrypt or Argon2 to slow attackers down.

Encryption Example with Key Management

Imagine you encrypt a diary:

• You use AES‑256 (symmetric) with a strong key.
• You keep the key secret.
• If you lose the key, you lose access to your diary.

Or you could use RSA (asymmetric):

• You give friends your public key to encrypt messages to you.
• You keep the private key to decrypt them.
• Only you can read the messages—no shared secret key needed.

Encoding Confusion Example

You see “SGVsbG8gV29ybGQh” (hello world in Base64). It's easy to decode—so encoding isn't about security; it's just a translation for safe transport.

 

Where and How Are These Used in Real Life?

Hashing:

• User authentication systems (password storage).
• Verifying file download integrity (e.g., software installers).
• Blockchain: each block stores the hash of the previous block—tamper evidence.

Encryption:

• Secure communication (WhatsApp, Gmail, VPNs).
• Full disk encryption on laptops or phones.
• Financial services, health records, government communication—privacy and confidentiality.

Encoding:

• Embedding images inside XML or JSON (Base64).
• Email MIME encoding attachments.
• URL encoding for safe web queries.

 

 

FAQs

What’s the difference between hashing and encryption?
Hashing converts data into a fixed, irreversible code used for verifying integrity or password checks. Encryption transforms data into ciphertext that can be reversed using the correct key for secure confidentiality.

Why use hashing for passwords instead of encryption?
Hashing is safer because it’s one‑way. Even if someone steals the hash, they can’t recover the password. Encryption is reversible—if the key is stolen, all encrypted passwords are at risk.

 

Conclusion

In this blog, we started with a stat: most websites use hashing—not encryption—for password protection. We defined:

• Hashing (one‑way, fixed output)—great for verification and password storage.
• Encryption (two‑way, key‑protected)—great for protecting message confidentiality.
• Encoding (simple transformation)—not security-related, just format conversion.

We compared all three side by side, offered simple examples for a 14‑year‑old, and advanced nuance for doctoral‑level readers—covering salt, secure algorithms, key management, and real‑world use cases. We also explained why password hashing is indispensable compared to password encryption, and why encoding isn't about security at all.

Whether you're new to cybersecurity or pursuing it in depth, understanding these differences is powerful knowledge. Keep asking questions, stay curious—and don’t store actual passwords anywhere. Use hashing wisely!