Hashing algorithms (SHA, MD5) in Cybersecurity - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create an MD5 hash of a string in Python.

Cybersecurity

import hashlib

hash_object = hashlib.md5()
hash_object.update([1].encode())
print(hash_object.hexdigest())

Drag options to blanks, or click blank then click option'

Adigest

Bhashlib

Cencode

Dpassword123

Attempts:

3 left

💡 Hint

Common Mistakes

Using the module name instead of the string to hash.

Passing the encode method instead of calling it on the string.

The string password123 is encoded and passed to the MD5 hash function to generate the hash.

2fill in blank

medium

Complete the code to create a SHA-256 hash of a string in Python.

Cybersecurity

import hashlib

hash_object = hashlib.[1]()
hash_object.update('hello world'.encode())
print(hash_object.hexdigest())

Drag options to blanks, or click blank then click option'

Asha1

Bmd5

Csha256

Dsha512

Attempts:

3 left

💡 Hint

Common Mistakes

Using MD5 instead of SHA-256.

Using uppercase letters in the function name.

The sha256 function from hashlib creates a SHA-256 hash object.

3fill in blank

hard

Fix the error in the code to correctly generate an MD5 hash.

Cybersecurity

import hashlib

hash_object = hashlib.md5('data'.[1]())
print(hash_object.hexdigest())

Drag options to blanks, or click blank then click option'

Aencode

Bdecode

Chexdigest

Dupdate

Attempts:

3 left

💡 Hint

Common Mistakes

Using decode instead of encode.

Calling hexdigest or update on the string.

The string must be encoded before passing to the MD5 function. Calling encode() converts the string to bytes.

4fill in blank

hard

Fill both blanks to create a SHA-1 hash of a string and print the hexadecimal digest.

Cybersecurity

import hashlib

hash_object = hashlib.[1]()
hash_object.[2]('example'.encode())
print(hash_object.hexdigest())

Drag options to blanks, or click blank then click option'

Asha1

Bupdate

Cmd5

Ddigest

Attempts:

3 left

💡 Hint

Common Mistakes

Using md5 instead of sha1.

Using digest instead of update to add data.

The sha1 function creates the hash object, and update feeds the encoded string to it.

5fill in blank

hard

Fill all three blanks to create a SHA-512 hash of a string and print the hexadecimal digest.

Cybersecurity

import hashlib

hash_object = hashlib.[1]()
hash_object.[2]('secure'.encode())
print(hash_object.[3]())

Drag options to blanks, or click blank then click option'

Asha512

Bupdate

Chexdigest

Ddigest

Attempts:

3 left

💡 Hint

Common Mistakes

Using digest instead of hexdigest for output.

Forgetting to encode the string before updating.

sha512 creates the hash object, update adds the encoded string, and hexdigest returns the hash as a readable hex string.

Practice

1. What is the primary purpose of hashing algorithms like MD5 and SHA in cybersecurity?

easy

A. To compress files to save storage space

B. To create a fixed-size code representing data for integrity verification

C. To encrypt data so only authorized users can read it

D. To generate random passwords automatically

Solution

1. Step 1: Understand hashing function role

   Hashing algorithms convert any input data into a fixed-size string of characters, called a hash, which uniquely represents the original data.

2. Step 2: Identify the main use in cybersecurity

   This fixed-size hash is mainly used to verify data integrity, ensuring data has not been altered.

3. Final Answer:

   To create a fixed-size code representing data for integrity verification -> Option B

4. Quick Check:

   Hashing = Data integrity check [OK]

Hint: Hashing creates unique codes to check data changes [OK]

Common Mistakes:

• Confusing hashing with encryption
• Thinking hashing compresses data
• Believing hashing generates passwords

2. Which of the following is the correct way to represent the MD5 hash of the string "hello"?

easy

A. A variable-length string depending on input size

B. A plain text copy of the original string

C. A 256-bit binary string

D. A 128-bit fixed-length hexadecimal string

Solution

1. Step 1: Recall MD5 hash size

   MD5 produces a fixed-size hash of 128 bits, usually shown as a 32-character hexadecimal string.

2. Step 2: Compare options with MD5 output format

   The 128-bit fixed-length hexadecimal string correctly describes MD5 output as a fixed-length hexadecimal string.

3. Final Answer:

   A 128-bit fixed-length hexadecimal string -> Option D

4. Quick Check:

   MD5 hash length = 128 bits [OK]

Hint: MD5 always outputs 128-bit hex strings [OK]

Common Mistakes:

• Thinking MD5 output length varies
• Confusing MD5 with SHA-256 length
• Assuming output is plain text

3. Consider this Python code snippet using hashlib:

import hashlib
hash_object = hashlib.sha256(b'password123')
hex_dig = hash_object.hexdigest()
print(hex_dig)

What will this code output?

medium

A. A 64-character hexadecimal string representing the SHA-256 hash of 'password123'

B. The original string 'password123'

C. An error because of incorrect input type

D. A 32-character hexadecimal string representing the MD5 hash

Solution

1. Step 1: Understand hashlib usage

   The code uses hashlib.sha256 to hash the byte string b'password123'. The hexdigest() method returns the hash as a hexadecimal string.

2. Step 2: Identify output length and content

   SHA-256 produces a 256-bit hash, which is 64 hex characters long. The output will be this 64-character hex string representing the hash.

3. Final Answer:

   A 64-character hexadecimal string representing the SHA-256 hash of 'password123' -> Option A

4. Quick Check:

   SHA-256 output length = 64 hex chars [OK]

Hint: SHA-256 hashes output 64 hex characters [OK]

Common Mistakes:

• Expecting original string as output
• Confusing input type causing error
• Mixing MD5 and SHA-256 output lengths

4. A developer wrote this code to hash a password using MD5:

import hashlib
password = 'mypassword'
hash = hashlib.md5(password)
print(hash.hexdigest())

What is the error in this code?

medium

A. The print statement syntax is incorrect

B. MD5 does not have a hexdigest() method

C. The input to md5() must be bytes, not a string

D. The hashlib module does not support MD5

Solution

1. Step 1: Check input type for hashlib.md5()

   hashlib.md5() requires a bytes-like object, but the code passes a string directly.

2. Step 2: Identify correct fix

   The string should be encoded to bytes using password.encode() before passing to md5().

3. Final Answer:

   The input to md5() must be bytes, not a string -> Option C

4. Quick Check:

   hashlib.md5() input = bytes [OK]

Hint: Always encode strings to bytes before hashing [OK]

Common Mistakes:

• Passing string directly without encoding
• Thinking hexdigest() is missing
• Assuming MD5 unsupported in hashlib

5. You want to securely store user passwords. Which approach is best considering hashing algorithms?

hard

A. Use SHA-256 with a unique salt for each password

B. Use MD5 without salt because it's faster

C. Store passwords in plain text for easy retrieval

D. Use SHA-1 without salt since it's widely supported

Solution

1. Step 1: Understand password storage best practices

   Storing passwords securely requires hashing with a strong algorithm and adding a unique salt to prevent attacks like rainbow tables.

2. Step 2: Evaluate options

   SHA-256 is stronger than MD5 and SHA-1. Using a unique salt per password improves security significantly.

3. Final Answer:

   Use SHA-256 with a unique salt for each password -> Option A

4. Quick Check:

   Strong hash + salt = secure password storage [OK]

Hint: Always salt and use strong hashes like SHA-256 [OK]

Common Mistakes:

• Using MD5 without salt thinking it's secure
• Storing passwords as plain text
• Using outdated SHA-1 without salt