CRYPTOGRAPHY and the Public Key Infrastructure.pptx

Cryptography is the science of securing information by transforming it into a format that is unreadable to unauthorized users. It employs mathematical techniques to encrypt and decrypt data, ensuring confidentiality, integrity, authentication, and non-repudiation. Cryptography is essential for securing communication over the internet, protecting sensitive information from eavesdropping, tampering, and forgery.

Public Key Infrastructure (PKI) is a critical component of modern cryptography that facilitates secure communication and transactions. PKI is a framework that manages digital certificates and public-key encryption, allowing users to verify each other’s identities and securely exchange information. It consists of several key elements, including certificate authorities (CAs) that issue and validate digital certificates, registration authorities (RAs) that help manage user identities, and a repository for storing these certificates.

In PKI, each user has a pair of keys: a public key that is shared with others and a private key that is kept secret. When someone wants to send secure information, they use the recipient's public key to encrypt the data. Only the recipient, with their corresponding private key, can decrypt and access this information. Additionally, PKI supports digital signatures, allowing individuals to confirm their identity and ensure that messages have not been altered.

Together, cryptography and PKI provide a robust framework for securing digital communications, enabling trust and security in online interactions, whether for personal use or within organizations.

1. CRYPTOGRAPHY and the PKI CompTIA Security+ (SY0-701) Amankwah Kwaku Bempah 2/25/2025 2/25/2025 1

2. Introduction To Cryptography Cryptography is the art of securing communication through encryption, ensuring that only authorised parties can access and interpret information. It is a fundamental part of cybersecurity, providing: confidentiality integrity authentication non-repudiation It is very significant in the world of cybersecurity. 2/25/2025 2

3. Historical Evolution Of CRYPTOGRAPHY Ancient Cryptography: Caesar Cipher, Scytale Cipher. Medieval & Renaissance: Vigenère Cipher, Substitution Ciphers Modern Cryptography: Enigma Machine, Public Key Infrastructure (PKI). 2/25/2025 3

4. Types Of Encryption Symmetric Encryption: Uses a single shared key (e.g., AES, DES). Asymmetric Encryption: Uses a public-private key pair (e.g., RSA, ECC). Key Exchange Mechanism: Diffie-Hellman, ECDH. 2/25/2025 4

5. Hashing and Integrity Purpose: Ensures data integrity, prevents unauthorised modification. Common Algorithms: MD5 (weak), SHA-256, SHA-3. Salting & Key Stretching: Strengthens password security. 2/25/2025 5

6. Digital Signatures & Certificates Ensures: Authentication and non-repudiation. How it works: Signed with private key, verified with public key. Certificate Authorities (Cas): Issue and verify certificates. 2/25/2025 6

7. Cryptographic Attacks Downgrade Attack: Forces weaker encryption. Collision Attack: Two different inputs produce the same hash. Brute Force Attack: Tries every possible key combination. 2/25/2025 7

8. Public Key Infrastructure (PKI) Purpose: Manages digital certificates for secure communication. Components: CA (Certificate Authority), CRL (Certificate Revocation List), OCSP (Online Certificate Status Protocol). Use Cases: SSL/TLS for websites, email encryption, secure authentication. 2/25/2025 8

9. Conclusion Cryptography is crucial for secure communication and data protection. Understanding encryption types, digital signatures, and PKI is key for cybersecurity. Stay updated on cryptographic threats and best practices. 2/25/2025 9