Cryptography in Everyday Life

Messaging Apps

When you send a message using apps like WhatsApp or Signal, cryptography keeps your conversation private. These apps use encryption to turn your message into a code that only the person you are talking to can read. If someone else tries to see your message, all they see is a jumble of letters and numbers.

Example:

• You type "Hello!" in a chat app;
• The app turns "Hello!" into something unreadable like j43kd8!;
• Only your friend’s app can turn it back into "Hello!".

Secure Websites

When you visit a website that starts with https://, cryptography helps keep your information safe. This is important when you enter passwords or credit card numbers online. The lock icon in your browser means your connection is encrypted.

Example:

• You visit https://www.bank.com;
• Cryptography scrambles your data so no one can steal your information as it travels across the internet.

Password Protection

Websites use cryptography to protect your passwords. When you create a password, the site turns it into a special code called a hash. Even the website cannot see your real password—only the coded version is stored.

Example:

• You choose the password "MyDog123";
• The website saves something like a9f8b2c1 instead of "MyDog123";
• If someone breaks into the website, they only see the code, not your real password.

Online Payments

When you shop online, cryptography keeps your payment details safe. Payment systems use encryption to protect your credit card number and other information during the transaction.

Example:

• You enter your card number to buy a book online;
• Cryptography ensures only the payment company can read your card number;
• Hackers cannot steal your information while it is being sent.

Everyday Security

You use cryptography every day—often without realizing it. From texting friends to shopping online, cryptography helps keep your personal information private and secure.