Confidentiality
Prevents unauthorized people from viewing private or sensitive information.
PRIVATE DATA
Encryption Systems Active
CYBERSECURITY LIFE • DATA PROTECTION
Understanding Cryptography
Cryptography protects sensitive information by transforming readable data into secure, encoded content. It helps keep passwords, financial information, personal messages, files, and online communications private and trustworthy.
ENCRYPTED
AES-256
RSA
SHA-256
TLS
THE FOUNDATION OF SECURE COMMUNICATION
What Is Cryptography?
Cryptography is the practice of protecting information through mathematical techniques. It converts normal readable information, known as plaintext, into encoded information called ciphertext. Only an authorized person or system with the correct key should be able to convert the ciphertext back into readable data.
01
Plaintext
The original readable message, password, document, or other information before encryption is applied.
➜
Encryption
02
Cryptographic Key
A secret or public mathematical value used by an encryption algorithm to protect or unlock data.
➜
Encoded
03
Ciphertext
The scrambled and unreadable result produced after the plaintext has been encrypted.
CORE SECURITY OBJECTIVES
What Cryptography Protects
Cryptography supports several important cybersecurity goals that help organizations and individuals protect information.
Integrity
Helps verify that information has not been secretly changed, damaged, or manipulated.
VERIFIED DATA
Authentication
Confirms that a user, device, website, or message is truly from the claimed source.
IDENTITY CONFIRMED
Non-Repudiation
Provides evidence that a person performed an action, such as signing or sending a digital document.
ACTION RECORDED
CRYPTOGRAPHIC METHODS
Major Types of Cryptography
Different cryptographic methods are used depending on how information must be protected, shared, or verified.
TYPE 01
Symmetric Encryption
Symmetric encryption uses the same secret key to encrypt and decrypt information. It is fast and works well for protecting large amounts of data.
Plaintext
＋ Secret Key →
Ciphertext
Common algorithms
Common uses:
File encryption, disk encryption, database protection,
backups, and secure network traffic.
TYPE 02
Asymmetric Encryption
Asymmetric encryption uses two related keys. A public key can be shared with others, while the private key must remain secret and protected.
🔓
Public Key
Shared openly
⇄
🔒
Private Key
Kept secret
Common algorithms
Common uses:
Secure key exchange, digital certificates, email encryption,
digital signatures, and HTTPS.
TYPE 03
Hashing
Hashing converts information into a fixed-length value called a hash or message digest. It is designed to be one-way, meaning the original information should not be recovered from the hash.
CyberSecurityLife
→ SHA-256 →
9A7F...E42C
Common algorithms
Common uses:
Password storage, integrity checking, digital signatures,
file verification, and blockchain systems.
METHOD COMPARISON
Encryption and Hashing Compared
| Method | Keys Used | Reversible | Primary Purpose | Examples |
|---|---|---|---|---|
| Symmetric Encryption | One shared secret key | Yes | Fast data protection | AES, ChaCha20 |
| Asymmetric Encryption | Public and private key | Yes | Secure communication and identity | RSA, ECC |
| Hashing | No encryption key | No | Integrity and verification | SHA-256, Argon2 |
TRUSTED DIGITAL COMMUNICATION
Digital Signatures
A digital signature uses asymmetric cryptography and hashing to verify who created a message or document and confirm that the information has not been changed.
01
Create a Hash
The document is processed through a hashing algorithm.
02
Sign with Private Key
The sender protects the hash using their private key.
03
Verify with Public Key
The recipient uses the sender's public key to verify the signature and document integrity.
signature-verification.log
$ verify-signature secure-document.pdf
[INFO] Calculating document hash...
[INFO] Reading public certificate...
[INFO] Comparing signature values...
[SUCCESS] Signature is valid.
[SUCCESS] Document integrity confirmed.
$
PUBLIC KEY INFRASTRUCTURE
Certificates and Website Security
Public Key Infrastructure, commonly called PKI, manages digital certificates and public keys. It helps users verify that they are communicating with a legitimate website, organization, service, or individual.
Digital Certificate
Connects a public key to an identified website, organization, device, or person.
Certificate Authority
A trusted organization that issues and verifies digital certificates.
HTTPS and TLS
Protects data sent between a web browser and a website through encrypted communication.
Chain of Trust
Allows devices and browsers to verify certificates through trusted root and intermediate authorities.
🛡️
SECURE CONNECTION
Encrypted with Transport Layer Security
Information transmitted between the browser and the website is protected from unauthorized interception.
EVERYDAY PROTECTION
Where Cryptography Is Used
Cryptography operates behind the scenes in many technologies and services used every day.
Online Banking
Protects account logins, payments, transfers, and financial information.
Mobile Devices
Secures stored files, device passwords, applications, and biometric authentication data.
Secure Messaging
Helps protect conversations through end-to-end encryption.
Email Security
Supports message encryption, identity verification, and digital signatures.
Cloud Storage
Protects files while they are stored and while they travel across networks.
Online Shopping
Secures customer information, passwords, payment details, and checkout sessions.
Digital Identity
Helps verify users, devices, certificates, and trusted online services.
Blockchain
Uses hashing and digital signatures to protect transactions and maintain record integrity.
SECURITY RISKS
Threats to Cryptographic Systems
Strong algorithms can still be weakened by poor implementation, stolen keys, weak passwords, outdated standards, or incorrect security practices.
Weak Algorithms
Older cryptographic algorithms may contain weaknesses that modern computers can exploit.
Key Theft
Attackers who obtain a private or secret key may gain access to protected information.
Brute-Force Attacks
Automated tools may attempt many passwords or keys until the correct value is discovered.
Man-in-the-Middle Attacks
An attacker may intercept communication and impersonate one or both participants.
Poor Key Management
Keys that are stored insecurely, reused, shared, or never replaced can compromise an entire system.
Implementation Errors
Programming mistakes or incorrect configurations may expose information even when strong algorithms are used.
SECURE IMPLEMENTATION
Cryptography Best Practices
Cryptography should be implemented carefully and supported by strong security policies, secure programming, and proper key management.
✓
Use trusted and modern encryption algorithms such as AES and properly configured TLS.
✓
Protect private keys and secret keys from unauthorized access.
✓
Use strong random number generation when creating keys, tokens, and passwords.
✓
Replace compromised keys and rotate sensitive keys on an appropriate schedule.
✓
Store passwords with secure password-hashing algorithms, salts, and appropriate work factors.
✓
Avoid designing custom cryptographic algorithms without expert review and extensive testing.
KEY MANAGEMENT SYSTEM
ONLINE
🔑
Encryption
AES-256
Key Status
Protected
Access Control
Authorized
Integrity Check
Passed
KNOWLEDGE CHECK
Test Your Understanding
Which cryptographic method is designed to produce a one-way, fixed-length value for verifying data integrity?
Answer: Hashing creates a fixed-length message digest and is commonly used to verify integrity.
CONTINUE YOUR CYBERSECURITY JOURNEY
Protect Data Through Strong Encryption
Cryptography is a major part of secure websites, networks, applications, operating systems, cloud platforms, and digital communication. Continue exploring the technologies and security principles that protect modern information systems.
🔐