Multi-factor authentication (MFA) in Cybersecurity - Step-by-Step Execution

Concept Flow - Multi-factor authentication (MFA)

User enters username & password

↓

System checks password correctness

↓

Prompt for 2nd factor

↓

User provides 2nd factor

↓

System verifies 2nd factor

↓

Access granted

The user first enters their password. If correct, the system asks for a second factor. If both factors are correct, access is granted; otherwise, access is denied.

Execution Sample

Cybersecurity

1. Enter username and password
2. Check password correctness
3. If correct, prompt for second factor
4. Verify second factor
5. Grant or deny access

This flow shows how MFA requires two steps of verification before allowing access.

Analysis Table

Step	Action	Input	Check/Condition	Result	Next Step
1	User enters credentials	username + password	Password correct?	Yes	Prompt for 2nd factor
2	User provides 2nd factor	e.g. code from phone	2nd factor valid?	Yes	Access granted
3	End	-	-	User logged in	-

💡 Access granted only if both password and second factor are correct

State Tracker

Variable	Start	After Step 1	After Step 2	Final
password_correct	False	True	True	True
second_factor_valid	False	False	True	True
access_granted	False	False	True	True

Key Insights - 2 Insights

Why is entering the correct password alone not enough to get access?

Because MFA requires a second factor to verify identity, as shown in execution_table step 2 where access is only granted after the second factor is validated.

What happens if the second factor is incorrect?

Access is denied even if the password is correct, as the system checks both factors before granting access (see execution_table step 2).

Visual Quiz - 3 Questions

Look at the execution_table, what is the result after Step 1 if the password is correct?

A Access granted

B Prompt for second factor

C Access denied

D End process

💡 Hint

Check the 'Result' and 'Next Step' columns in execution_table row for Step 1

At which step does the system finally grant access?

A Step 2

B Step 3

C Step 1

D Access is never granted

💡 Hint

Look at the 'Result' column in execution_table for Step 2

If the second factor is invalid, what would change in the execution_table?

A Prompt for second factor again at Step 1

B Access granted at Step 2

C Access denied at Step 2

D Password check fails at Step 1

💡 Hint

Refer to the 'Check/Condition' and 'Result' columns in execution_table Step 2

Concept Snapshot

Multi-factor authentication (MFA) requires two or more verification steps.
First, the user enters a password.
Then, a second factor like a code or biometric is required.
Both must be correct to grant access.
This adds extra security beyond just a password.

Full Transcript

Multi-factor authentication (MFA) is a security process where a user must provide two different types of information to access an account. First, the user enters their username and password. The system checks if the password is correct. If it is, the system asks for a second factor, such as a code from a phone app or a fingerprint. The user provides this second factor, and the system verifies it. Only if both the password and the second factor are correct does the system grant access. If either is wrong, access is denied. This process helps protect accounts by making it harder for unauthorized people to get in, even if they know the password.