Security Engineering: Advanced Systems & Cryptography

Identify how subjects access objects and manage information flow through computers and programs. Design and maintain trusted hardware, software, and processes to establish a secure, end-to-end trusted path.

Explore security models as ink and paper standards and their real world implementations, highlighting how developers adapt recipes into tailored systems while respecting business policies.

Explore three foundational security models—state machine, information flow, and non-interference—and how their true alignment enables a trusted computing base and a secure information environment.

Explore the Bell-LaPadula model, a mandatory access control framework focused on confidentiality, using a lattice of labels from top secret to unclassified to control information flow among subjects and objects.

Explain the Bell-LaPadula confidentiality model within mandatory access control. Apply the star property no read up, no write down, and the strong star property for single-layer access.

Explore the Biba integrity model built on mandatory access control and lattice labels, guarding information integrity through no read down, no write up, and polyinstantiation against aggregation and inference.

Explain how Bel LaPadula rules govern reading and writing using simple, star, and strong star properties, with Bobo's secret clearance and five files to illustrate access decisions.

Explore the Clark-Wilson model’s approach to preserving integrity of valuable information assets, highlighting transformation procedures, constrained versus unconstrained data items, and periodic verification for internal and external consistency.

Explore the Brewer-Nash model that defends against conflicts of interest by dynamically assembling access control lists and enforcing a Chinese wall after a subject accesses a data set.

Explore trusted computing base, its perimeter of hardware, firmware, operating system, and apps, and how reference monitors, memory protection, and ring architecture enforce trust, with blue screen and trusted recovery.

Explore the trusted computing security evaluation criteria as a US government effort to establish a trusted computing base and trusted path between subjects and objects, via orange and red books.

Explore how vendors certify hardware, the US government's accreditation, and the certification levels from D to A1, including mandatory and discretionary access control.

Explore how information technology security evaluation criteria extend the trusted computing base from TTIC SEC; map functionality and assurance ratings across standards.

This lecture explains the common criteria, ISO adopted, and how seven testing levels from functional to formal verification establish trusted government systems through protection profiles and the evaluated products list.

Explore computer hardware to establish a trusted path, examining CPU components (ALU, registers, control unit), memory hierarchy, BIOS/ROM, storage, and network interface card security controls shaping choke points and segmentation.

Explore the processing unit's core components—the arithmetic logic unit, the control unit, and registers—and how the control unit fetches instructions and data from the process table for the execute cycle.

Compare reduced instruction set computing (RISC) and complex instruction set computing (CISC), with a left-turn analogy, and note Intel-based systems widely use CISC.

Explore scalar versus super scalar processing and how pipelining increases CPU throughput. Note that hardware and software must support these techniques, though they are outdated yet relevant for CISSP exams.

Explore the motherboard as a multi-layer printed circuit board that houses the CPU, RAM, firmware, and buses, with connectors to peripherals and security implications of physical segmentation.

Examine memory hierarchy from registers to RAM, detailing level one and two caches, SRAM and DRAM, volatility, refresh, and power trade-offs that influence CPU speed and capacity.

Explore virtual memory and swap files that extend memory, and learn how the memory manager moves data to disk, revealing performance costs and security implications of page files.

Understand how the memory manager abstracts RAM with two-gigabyte logical addresses, enforces protection via the local security authority, and uses paging, page outs, and page ins to manage memory.

Explore read-only memory (rom) as a non-volatile store for firmware and the bios, used to bootstrap the system and load basic drivers into ram, with tpm in bios configuration.

Explore real memory, or primary memory, including registers, caches, and RAM, as volatile storage. Contrast with secondary memory, nonvolatile storage like hard drives and USBs, slower and farther from CPU.

The TPM chip enables whole disk encryption by securely storing the decryption key and supports trusted boot by hashing hardware configuration and kernel files to deny boot if tampered.

Trace the boot process from power-on through bios, bootstrap os, and low-level drivers to the graphical user interface and login.

Examine the boundary between user mode and kernel mode, where untrusted user applications meet the trusted kernel and its executive services on bare metal hardware and a hardware abstraction layer.

Explore the four ring architecture defining security zones around the kernel, from ring zero to ring three, with APIs governing access by the memory manager and device drivers.

Explains kernel mode's full authority, why malware seeks rootkits, and how to defend by validating device drivers from vendor sites, using hashes and trusted boot with TPM.

Explore how operating systems support multi processing, multitasking, and multi-threaded execution from single cpus to multi-core systems, including the hardware abstraction layer and the shift from cooperative to preemptive scheduling.

Explore how the memory manager allocates ram for a multi‑process application, protects the buffer via the security kernel, and manages thread data and pointers.

Unfiltered input can overflow a buffer and overwrite a memory pointer, forcing execution of malicious script. It demonstrates how input filtering prevents buffer overflow and protects memory, pointers, and processes.

Explore how a process spends most of its life in the blocked state, buffers data, then moves to ready and running as the control unit stages data toward the CPU.

Master memory management from allocation to reclamation, including garbage collection. Overwrite buffers securely to prevent memory leaks and protect data with ASLA, protected memory, and non-executable memory.

Enforce access control via the reference monitor that checks object ACLs and prevents race conditions by tightly aligning time of check and time of use within the secure boundary.

Protects the kernel and memory from violations by enforcing protected, non-paged memory; halts operations with a blue screen, dumps ram, and recovers via safe mode or trusted recovery.

Harden bastion hosts and infrastructure to reduce the attack surface by limiting services to one or two per box and enabling weekly patches, daily malware updates, HIPs, and firewall controls.

Explore virtualization by examining how a hypervisor abstracts hardware to run guest operating systems and multiple virtual machines on a single host.

Explains virtualization by running many virtual machines on fewer bare metal machines to boost hardware utilization from 15% to 80-90%, enabling server consolidation, high availability, isolation, backups, snapshots, and scaling.

Examine virtualization software and hypervisors like VMware ESXi, Hyper-V, VirtualBox, and Xen to run multiple guest operating systems and deploy virtual networks and appliances.

Explore virtual desktop infrastructure, where thin clients boot to a hosted desktop with a single patched operating system, highlighting licensing, hardening, and hypervisor security risks in multi-tenant environments.

Trace information systems architecture from mainframes and initial program load to modern client-server setups, where thin clients submit queries to back-end application servers that access centralized data repositories.

Address enterprise risks from mobile devices by implementing policies and NAC to quarantine and remediate devices with updates, firewall, antivirus, and backups, and enforce multifactor authentication and whole disk encryption.

Learn how mobile device management uses app whitelisting, regular backups, remote wipe, and device location to secure corporate data while enforcing acceptable use policies and controlled network access.

Investigate peer-to-peer computing in ad hoc networks where workstations act as both client and server, sharing resources, and assess security risks from malicious or infected nodes like BitTorrent and Kazaa.

Explore centralized, distributed, and decentralized architectures, highlighting co-location and parallel processing for fault tolerance. Emphasize data consistency, interoperable systems, and unified security policies across multiple locations.

Compare private and public cloud models, highlighting centralized control, high availability, and cost trade-offs; explain IaaS, PaaS, and SaaS and how providers affect security and management.

Negotiate strong penalties and liability in cloud provider contracts. Enforce compliance through verification, monitoring, audits, data access, breach notification, and clear termination terms.

Grid computing coordinates a cloud of clouds to provide massively large scale processing power and shared information assets, with Boink as middleware orchestrating task distribution, data formatting, and interoperability.

The internet of things will connect billions of devices, creating security vulnerabilities and privacy risks, with potential disruption to critical infrastructure via industrial controls and dnp3.

Explore multi-layer application architecture and how security acts at each boundary, from thin client interfaces to back-end servers, DMZs, and data repositories, ensuring data integrity via middleware translation.

Explain hierarchical, mesh, relational, and object-oriented databases, their data organization and relationships, and how a database management system handles authentication, permissions, and keys like primary and foreign keys.

Explore the object oriented database capable of storing non-textual content and compiled code. Learn concurrency controls: record locking, rollback, and two-phase commit with a moderator to preserve data integrity.

Explore semantic integrity through schema constraints that enforce data type, length, and reject illegal strings, and uphold entity and referential integrity with primary keys and foreign keys in relational databases.

Maintain redundancy with shadow databases on separate hardware updated in real time and consider disaster recovery across locations, meeting recovery point objectives with transaction journaling, backups, and clustered servers.

Examine poly instantiation in mandatory access control databases, where multiple versions of truth are labeled by classification and appended to primary keys to prevent aggregation and inference, preserving information integrity.

Combine middleware to normalize data from diverse databases and align schemas and constraints for the application. Use odbc, jdbc, and xml techniques to extract, document, and reconcile formatting conflicts.

Examine component object model, dcom, and orb technologies, including object linking and embedding, for cross-device and cross-language middleware that shares resources across networks.

Extract value from warehouses by aggregating databases, removing redundancy, standardizing references, and using a middleware layer to normalize schemas; mine a data mart for artificial intelligence-driven trends and predictive insights.

Explore ai-powered data aggregation and mining that uncover patterns boosting revenue through targeted marketing. Learn about data warehouses and data marts and face privacy risks from internet of things presence.

Explore web-based applications and enterprise single sign-on using SAML and Kerberos, with mutual authentication, tokens, and OpenID for consumer single sign-on on the public internet.

Explain how web servers push mobile code to browsers and why client-side execution creates security risks; summarize cookies, scripts, Java applets, and ActiveX controls, and session versus persistent cookies.

Explore cross-site scripting attacks, including non-persistent, persistent, and DOM-based variants, where client-side scripts reflect from poorly configured servers, stored comments, or cookies to compromise users.

Compare Java applets and ActiveX controls as browser mobile code, noting platform independence via the Java Virtual Machine, sandbox security, signing with authentic code, and Edge's security tradeoffs.

Explore web application security challenges, including browser and email threats, DNS poisoning, click jacking, phishing, and malicious attachments.

The lecture emphasizes input validation on the developer side for web apps to prevent buffer overflow and sql injection by denying unexpected input and validating form data before processing.

Explore the Open Web Application Security Project and its pen testing tools, focusing on the top ten risks, code review and testing guides, and remediation.

Introduce cryptography as the study of cryptology, the art of hiding and recovering message meaning to enable secure communication, while cryptanalysis tests and breaks algorithms and keys to assess strength.

Explore the five desirable cryptographic services—confidentiality, authentication, integrity, non repudiation, and secure key distribution—alongside how encryption provides authorization and integrity verification with hashing.

Explore how cryptography protects data at rest and in transit by using encryption algorithms, keys, and periodic key rotation through crypto periods to convert plaintext into ciphertext and back.

Explore symmetric and asymmetric key algorithms, public and private keys, hashing, digital signatures, and message authentication codes to ensure confidentiality, integrity, authenticity, and non repudiation.

Maximize ciphertext entropy to prevent pattern-based key exposure, balance the work factor with ciphertext cost, and secure key creation, distribution, and storage through well designed algorithms and user policies.

Understand how longer key length grows the key space to deter brute force, avoid key clustering and weak patterns, and compare symmetric 256-bit keys with longer asymmetric 2048–3072-bit keys.

Understand key management fundamentals, from cryptographic service providers creating keys to secure distribution of symmetric keys and private versus public keys, plus rotation, revocation, escrow, recovery, and lifetimes.

Learn hashing algorithms or message digests to verify data integrity without encryption, producing a fixed fingerprint; digital signatures with public keys provide strong authentication and non repudiation, unlike macs.

Explore how hashing algorithms process binary data by chunking bits and applying math to produce a hash value used to verify integrity, with md5 and sha-1 examples.

Explore hashing algorithms from parity and CRC to MD5, SHA-1, RIPEMD-160, and the SHA-2 family, emphasizing collision resistance and data integrity verification.

Examine what makes a hashing algorithm strong by prioritizing a higher hash output size, a high avalanche effect, and a low collision frequency to resist birthday attacks.

Combine hashing with symmetric-key algorithms to produce a message authentication code that authenticates the sender and verifies message integrity. However, two copies of the same key make authentication weak.

Combine hashing with asymmetric keys to produce a digital signature that provides strong authentication, integrity, and non repudiation, underpinning modern PKI and X.509 certificates.

Apply symmetric key algorithms, including block and stream ciphers, and learn how substitution and transposition techniques diffuse patterns to secure encryption and decryption, and trace origins to ancient hieroglyphics.

Explain how symmetric key cryptography delivers fast confidentiality with block ciphers, but offers weak authentication, weak integrity, no non-repudiation, and faces key distribution challenges.

Demonstrate how symmetric key algorithms convert plaintext to ciphertext using an encryption key, and decrypt ciphertext with the same key to reveal clear text, delivering fast, strong confidentiality.

Explore how symmetric key algorithms enable a weak form of authentication by sharing a secret key; decrypting with the correct key indicates likely authorship, while proving sender identity remains impossible.

Explore how symmetric key algorithms ensure confidentiality, why integrity verification may be weak, and how hashing shows data hasn't been altered while trust depends on sender authentication.

Examine symmetric key distribution and management, from insecure channels and prior association to securely sharing keys, the two key copies, and the n(n-1)/2 key-count formula for n users.

Explore historical symmetric key algorithms, including Atbash substitution, the Shetterly transposition, and Caesar shift ciphers, and learn how key choices and weaknesses affect cryptography.

Explore cryptanalysis of symmetric key systems, using frequency analysis to crack substitution ciphers and simple methods to crack transposition ciphers.

Examine the veneer cipher, a historical poly alphabetic system that uses a repeating key with plaintext and ciphertext. See how longer, randomized keys reduce patterns in encryption.

Explore how Boole's binary logic underpins modern cryptography, focusing on the exclusive or function and substitution boxes that combine plaintext and key material to produce encrypted outputs.

Explore how the exclusive or operation encrypts plaintext with a shared symmetric key to produce ciphertext in a substitution cipher, enabling secure decryption by the recipient.

Explore Kershaw's principle of security through the secrecy of the key, not the algorithm, and trace the development of the one time pad and symmetric key design from history.

Trace the evolution from Hebburn rotor to Enigma and red and purple machines, and see how FI style block ciphers—using substitution (confusion) and transposition (diffusion) across rounds—shape modern symmetric encryption.

Explore classical and modern symmetric ciphers, from des and triple des to aes, rc4, and blowfish, and learn how key streams, initialization vectors, prngs, and lfsrs shape secure encryption.

Understand how the data encryption standard uses a 64‑bit block and 56‑bit key. It applies 16 rounds of substitution and transposition and leads to triple DES with varied keys.

Explore the advanced encryption standard (aes) in detail, including 128-bit blocks, 128/192/256-bit keys with 10–14 rounds, and the NIST recommendation plus diffusion tools like salts, initialization vectors, and nonces.

Explore modes of operation for symmetric key block ciphers, focusing on electronic code book mode (ECB), its fast but weak patterns, and why it's unsuitable for multiple blocks.

Explore cipher block chaining (cbc) as a method that uses xor and a symmetric key block cipher to chain ciphertext with plaintext, enabling alteration detection.

Explore output feedback mode (ofb), a stream-like block cipher that uses a random initialization vector, encrypts it, and xor the result with each plaintext block, commonly used in satellite communications.

Cipher feedback mode is a stream mode that chains ciphertext with the next encryption block and xor with plaintext. Four modes—ecb, cbc, ofb, cfb—diffuse differently, with counter mode next.

Explore counter mode ctr: a fast, strong mode using a nonce and counter with a block cipher to generate key material. Xor with plaintext to produce ciphertext with no chaining.

Explore how symmetric keys and hashing produce a message authentication code (mac) to provide a weak form of authentication and integrity, and examine man-in-the-middle attacks and hash-value verification.

Explore how mac and hmac defend against man-in-the-middle attacks by hashing data and encrypting the hash with a shared symmetric key to ensure integrity and authenticity.

Explore asymmetric key cryptography, featuring public and private keys used to encrypt and decrypt, as Hellman, Diffie, and Merkle paved a hybrid system with symmetric keys and hashing.

Explore how asymmetric, symmetric, and hashing algorithms together deliver five key cryptographic services, including secure key distribution, session key encryption, data integrity, authentication, and non-repudiation.

Demonstrate how asymmetric and symmetric keys combine to provide fast confidentiality and secure key distribution, plus authentication through digital signatures and digital certificates.

Leverage asymmetric keys to encrypt symmetric session keys and hash values, delivering confidentiality and integrity. Apply a digital certificate and a digital signature for strong authentication and non repudiation.

Asymmetric keys have enormous key spaces and slow performance, so I use them to securely distribute symmetric keys. Bulk data stays encrypted with fast symmetric keys.

Explain secure key distribution by encrypting a symmetric session key with the recipient’s public key, enabling bulk data encryption, and ensuring integrity, authentication, and non-repudiation via digital signatures and hashing.

Explore how digital signatures verify message integrity, authenticity, and non repudiation through hash-based signing with private keys and certificate-backed public keys, and certificate authority validation.

Discover how asymmetric cryptography, digital certificates, and hashing enable confidential, authenticated, and non-repudiation-enabled message delivery, using a public-private key exchange and a symmetric session key.

Demonstrates confidential multi-recipient messaging by signing the hash with a private key, then encrypting a symmetric session key with each recipient's public key using trusted certificates from a certification authority.

Explore how ssl and tls secure internet communications by authenticating servers, distributing symmetric keys, and supporting mutual authentication and certificates to establish a secure channel.

Explore Diffie-Hellman, the first asymmetric key algorithm, enabling two endpoints to derive a shared symmetric key over an insecure channel. Utilizes public and private keys via discrete logarithms.

Explore rsa’s trapdoor function based on factoring numbers, delivering confidentiality, authentication, integrity, non repudiation, and key distribution; compare to El-Gamal and elliptic curve systems with x.509 and sha-2.

Concludes asymmetric key algorithms by reviewing Diffie-Hellman, RSA, El-Gamal, elliptic-curve crypto, knapsack, and Lucas, and highlights the five cryptographic services they can provide.