Password authentication protocols are the backbone of secure logins, ensuring only authorized users can access systems and data. They work by verifying the user's identity using a combination of a username and password.
Here's a breakdown of how it works:
1. User Input
- The user enters their username and password into the login form.
- The client software (e.g., web browser) encrypts the password using a hashing algorithm.
- The encrypted password, along with the username, is sent to the server.
2. Server Verification
- The server retrieves the user's stored password hash from its database.
- The server hashes the received password using the same algorithm.
- The server compares the newly generated hash with the stored hash.
3. Authentication
- If the hashes match, the server authenticates the user. This means the server verifies the user's identity and grants access to the system.
- If the hashes don't match, the server denies access. This indicates an incorrect password or a potential security breach.
Key Concepts
- Hashing: A one-way function that converts a string of text into a fixed-length string of characters. It's impossible to reverse the process, meaning you can't get the original password back from the hash.
- Password Storage: Servers don't store passwords in plain text. Instead, they store password hashes, making it safer if the database is compromised.
Example
Imagine you're logging into your online banking account. You enter your username and password. Your browser encrypts the password using a hashing algorithm and sends it to the bank's server. The server retrieves your stored password hash from its database and hashes the password you just entered. If the two hashes match, you're granted access to your account.
Benefits of Password Authentication
- Security: Using password hashing makes it harder for attackers to steal passwords, even if they gain access to the database.
- Simplicity: It's a familiar and easy-to-understand authentication method for most users.
Limitations
- Vulnerability to brute-force attacks: Attackers can try guessing passwords repeatedly until they find a match.
- Phishing scams: Users might be tricked into entering their credentials on fake websites.
