PKI Essentials-Understand the security of Digital Identities

Explore key cryptographic solutions, from PKI and certificates to encryption, hashing and salting, digital signatures, and obfuscation, and learn how blockchain and open public ledgers secure digital identities.

Explore how public key infrastructure secures digital identities by using private and public keys, certificates, and asymmetric versus symmetric encryption to protect emails and online data.

Explain the tls handshake from client hello to finished messages, including certificate validation by a certificate authority and derivation of session keys for an encrypted browser and server channel.

Explore PKI infrastructure and key pairs, including public and private keys, encryption and decryption, certificate authorities, and key escrow that protect online data.

Explore why encryption matters and how it protects data from full disk to file-level, volume, and database encryption, plus data in transit, asymmetric and symmetric cryptography, and key lengths.

discover how to apply encryption at multiple levels, from full disk encryption to partition, file, and volume encryption. explore database protections such as transparent data encryption and record-level encryption.

Protect data in transit with transport encryption, ensuring privacy, integrity, and authentication through TLS and SSL, while PKI infrastructure and certificates underpin end-to-end security.

Explore how symmetric encryption uses a single key to convert plain text to cipher text, supports key management, and employs AES, DES, and 3DES for wifi and online banking security.

Understand how asymmetric encryption uses public and private keys to secure data and enable key exchange. See how ssl/tls and pgp rely on this, with digital certificates and private-key protection.

Explain how key exchange mechanisms, including diffie-hellman, establish a shared secret over insecure channels and enable secure https and vpn connections, while highlighting man-in-the-middle risks and authentication.

Examine key exchange algorithms, including Diffie-Hellman, RSA key exchange, and elliptic curve Diffie-Hellman, their vulnerabilities and performance, and their roles in SSL, TLS, and VPN security, plus quantum key distribution.

Explore how key length drives encryption security and efficiency, comparing RSA, AES, and ECC with examples like 2048-bit RSA and 256-bit ECC, and its impact on everyday protection.

Explore encryption and PKI tools, including TPM, HSM, key management systems, and secure enclaves, and learn how they secure keys in today's corporate world.

Explore how the trusted platform module works as a hardware-based security, safeguarding cryptographic keys. Learn its 2.0 evolution and roles in secure boot and full disk encryption across devices.

Hsm is a physical device outside the computer that securely generates, stores, and manages key life cycles in an environment. It enables on-device encryption, authentication, and signing for compliant transactions.

Discover how KMS, a key management system, automates the cryptographic key lifecycle from generation to rotation and deletion, while enforcing usage policies for secure cloud data.

Secure enclaves create a protected, isolated area inside processors to safeguard cryptography and sensitive data, boosting corporate security by protecting trade secrets, client information, and secure transactions.

Explore obfuscation, rooted in cryptography and data hiding, disguising code to deter reverse engineering and protect intellectual property in software, games, finance, IoT, with steganography, tokenization, and data masking.

Steganography hides information and the existence of messages, tracing its roots from ancient Greece to the digital age, and it supports privacy and security in IT.

Explore tokenization, a process that replaces sensitive data with tokens stored in a token vault, reducing data breach risk and aiding PCI DSS compliance in e-commerce and financial transactions.

Explore data masking as a practical privacy technique that disguises sensitive data while preserving usability. Learn substitution, shuffling, encryption, and tokenization to protect privacy in healthcare and finance.

Explore the types of data masking, including static, dynamic, and on the fly masking. Compare de-identification and anonymization and see how they protect data across non-production and production environments.

Explore data masking techniques: substitution, shuffling, blurring, and character scrambling to protect sensitive data in production while preserving analytic utility.

Explore how hash functions convert data into a fixed-size output to guard data integrity, provide a data fingerprint, and enable secure password storage with one-way, fast, and deterministic operations.

Hash functions secure passwords by storing hashes instead of the actual passwords. They enable digital signatures, verify downloads, support blockchain integrity, and aid file verification and deduplication.

Explore the history and evolution of hashing, from MD5 to SHA-256, noting differences in output size and security. Discover contributors and how hash algorithms underpin SSL, blockchain, and quantum-resistant hash research.

Traces hashing algorithm history, highlighting md5's collision vulnerabilities and sha-1's weakening security. Shows sha-256's 256-bit strength for secure protocols and blockchain, with real-world attacks like Flame and Google's 2017 collision.

Select hashing algorithms for digital identities by balancing security and speed. Use SHA-256 for strong collision resistance, while MD5 and SHA-1 trade speed for vulnerabilities in SSL certificates and blockchain.

Explore hashing vulnerabilities from LinkedIn's unsalted hashes and Yahoo's md5 weaknesses; learn to defend with salting and sha-256.

Explore how salting strengthens passwords via 128-bit salt generation, concatenation, and slow hashing with pbkdf2, bcrypt, or scrypt; store salts in plain text and hashes in binary.

Explore digital signatures as electronic fingerprints authenticating documents via public key cryptography. Trace 1970s origins with Whitfield Diffie and Martin Hellman, and note industry leaders like Adobe Sign and DocuSign.

Digital signatures provide authentication, integrity, and non-repudiation, enabling trust and secure online transactions across legal, financial, and governmental communications.

Understand how digital signatures use private signing keys and public verification keys, with RSA or ECDSA and hashing to secure integrity, while recognizing evolving quantum threats and quantum-resistant research.

Create and verify digital signatures by hashing content and encrypting the hash with the signer’s private key. Verification uses the public key and certificate authorities under standards to ensure authenticity.

Explains how digital signatures protect data integrity and non-repudiation by using a private key to sign a document’s hash, enabling tampering detection with a public key verification.

Compare rsa, dsa, and ecdsa for digital signatures, noting rsa's widespread browser and email use, dsa in government, and ecdsa efficiency for blockchain, within public key cryptography and x509 standards.

Explore digital signature standards, including PKCS, RSA, DSS, and X509, their roles in secure communications, blockchain, and regulated industries, and how to choose standards for quantum cryptography.

Explore elliptic curve cryptography (ECC), delivering RSA-equivalent security with smaller keys, enabling efficient EC digital signatures (ECDSA) for mobile devices, smart cards, and cryptocurrencies.

Explore key stretching as a cornerstone of digital security by rehashing passwords with algorithms like bcrypt and pbkdf2 to slow attackers and protect password data.

Explore key stretching with Bruce Schneier's bcrypt approach, adapting to faster computers to protect passwords against cracking, and learn how his work in Applied Cryptography shapes security practices.

Explore blockchain basics: a distributed digital ledger, blocks, and smart contracts, with applications from Bitcoin and Ethereum to supply chain, digital identities, voting, and DeFi.

Blockchain is a decentralized digital ledger where each transaction updates copies across many computers, making records tamper-evident and transparent for uses from currencies like Bitcoin to land and food tracking.

Explore how blockchain enhances data security and transparency across real estate, energy, education, and art, with tamper-proof ledgers, verifiable credentials, and provenance tracking.

Explore the origins of internet security from arpanet to the web, and learn how SSL and digital certificates enable HTTPS, authentication, and digital trust.

Trace the evolution of cryptography from ancient codes to modern PKI, digital certificates, and SSL and TLS, highlighting key milestones that secure digital identities.

SSL established a secure channel between web browsers and servers, enabling encrypted data and trusted online transactions, and evolved into TLS as the standard for securing internet communications.

Explore how ssl 3.0 vulnerabilities and the poodle attack drove the evolution to tls, delivering stronger encryption, better authentication, and more efficient protocol design up to tls 1.3.

Analyze SSL vulnerabilities, including the Poodle attack on SSL 3.0, and how TLS upgrades strengthen encryption, prevent downgrade attacks, and improve certificate validation to protect digital identities.

Explore how SSL's flaws and outdated algorithms like RC4 and DS prompted the transition to TLS, with improved handshakes, key exchange, and security features such as Diffie-Hellman and HMAC.

Trace the evolution of TLS from 1.0 to 1.3, outlining vulnerabilities like Poodle and Beast, and enhancements such as explicit IVs, forward secrecy, SHA-256, GCM, ChaCha20-Poly1305, and elliptic curve Diffie-Hellman.

Explore the rise of certificate authorities, from VeriSign's early SSL trust to modern PKI standards, audits, and criticisms, and learn how Let's Encrypt democratizes access to secure certificates.

Explore the certificate authority hierarchy and the chain of trust, tracing how browsers verify site certificates from intermediates to root CAs using Google, Microsoft, and Cloudflare examples.

Explore the hierarchical trust model of certificate authorities, from offline root CAs to rigorous validation and logging. Use hardware security modules and ongoing cryptographic updates to sustain digital identity security.

Navigate the root certificate authority as the trust anchor in the certificate chain, issuing to intermediate CAs and enforcing policies, lifespans, and revocation to protect integrity.

Explore how intermediate certificate authorities bridge the chain of trust from root CA to end-entity certificates, enabling scalable PKI with offline root security and tailored policies.

Learn what a certificate revocation list (CRL) is and why we revoke certificates, how serial numbers are published, and how OCSP provides real-time revocation status.

Discover how certificate authorities issue certificates and how OCSP checks replace growing CRLs to verify certificate status (good, revoked, or unknown) on the browser.

Learn how the browser finds the ocsp responder url via the aia extension in a site's certificate. Verify the certificate status and how ocsp stapling can improve performance.

Understand self-signed certificates, created by organizations without external authorities, and why browsers warn about them; learn their use for encryption at basic level in corporate networks and internal development environments.

Understand how third party certificates issued by certificate authorities enable secure encrypted communications online, with domain and extended validation.

Explore what a certificate signing request (CSR) is, its key components—public key, subject information, signature algorithm—and how a certificate authority issues and you install an SSL/TLS certificate.

discover how wild card certificates secure multiple subdomains under one certificate, offering cost savings and simplified management, but sharing a single private key risks all subdomains if compromised.

Learn how to purchase and secure a domain from registrars like GoDaddy, evaluate pricing and registration options, and enable domain protection with two-factor authentication to safeguard digital identities.

Build a Linux Ubuntu 20.04 virtual machine in Azure to test PKI infrastructure, connect via PuTTY using the public IP, and configure a DNS A record to map the domain.

Map the root domain to the server with an A record at the registrar, pointing to the public IP and time to live, and prepare the web server and certificates.

Install certbot and the Apache plugin to obtain a Let's Encrypt SSL certificate for the site, including www, then update DNS with a www A record and wait for propagation.

Verify DNS propagation, obtain a Let's Encrypt certificate, and validate the chain of trust from ISRG root X1 to R3, backing up keys under /etc/letsencrypt and redirecting http to https.

Learn how to use certbot with Letsencrypt to renew certificates, list existing ones, perform dry runs, revoke, and delete certificates, while backing up and tracking certificate and key paths.

Learn to create a private key with OpenSSL, generate a self-signed certificate, and configure Apache for HTTPS, while noting that self-signed certs lack CA validation and aren’t trusted by browsers.