Cryptography: AES, RSA, ECC, SHA and RoT Secure Boot.

Explore the AES algorithm, its symmetric key basis, its derivation from DES, and key expansion, including decryption with the reversed key and GCM mode.

Explore how AES uses a substitution-permutation network with sub bytes, shift rows, mix columns, and round keys produced by a key expansion module; encryption and decryption mirror each other.

Explore AES operation in 128-bit blocks, detailing substitute bytes, shift rows, mix columns, and add round key, with S-box and inverse S-box insights for encryption and decryption.

Explore how aes modes adapt to security requirements, comparing ecb, cbc, cfb, ofb, and ctr, and define key terms like plaintext, ciphertext, key, and initialization vector.

Explain aes in ecb mode, where each block uses the same key, producing identical ciphertext for repeated plaintext, highlighting its security vulnerabilities and unsuitability for secure environments.

Explain how CBC mode uses an initialization vector and ciphertext chaining to encrypt and decrypt, with XOR via the IV and prior ciphertext, and warn about a dynamic IV risk.

Explore cipher feedback mode (cfb): encrypt the initialization vector with the key, xor with plaintext to form ciphertext, and note how decryption reverses this process and the replay attack risk.

Apply aes in ofb mode to generate keystream by encrypting the initialization vector and xor-ing with plaintext to form ciphertext. This design risks Mallory modifying ciphertext via the keystream.

aes-ctr mode encrypts a counter and xors it with plaintext to form ciphertext, incrementing per block; decryption repeats the step to recover plaintext, with no initialization vector.

Learn aes gcm mode by encrypting plaintext with a key and associated data to generate a tag for integrity, then decrypt by validating the tag to prevent modification.

Explore the RSA algorithm, its public and private keys, and the encryption and decryption workflow, including key generation, ciphertext, and the role of elliptic curve cryptography as another asymmetric approach.

Explore RSA history: the asymmetric cryptography algorithm was developed by Rivest, Shamir, and Adleman in 1977, using public key E and private key D with 1024–2048 bit keys.

Explore RSA features: how asymmetric key cryptography uses two keys for encryption and decryption, with public key n and e, private key n and d, and secure key distribution.

Understand rsa: generate n as product of primes p and q; encrypt with public key (n, e) and decrypt with private key (d, n); security relies on key size.

RSA key generation selects two primes p and q, computes n and φ(n), then derives e and d for the public and private keys and ensures secure key exchange.

Explore how the RSA algorithm uses the public key n and e to encrypt and the private key d to decrypt, covering key generation and crypto analysis.

Explore elliptic curve cryptography, an asymmetric key system that generates public and private keys from elliptic curve math. ECC offers stronger security with smaller keys, e.g., 384-bit versus RSA 7680-bit.

Explore the sha secure hashing algorithm, which uses no keys to turn input messages into hash values, shows avalanche effects, and introduces sha types and hmac implementation.

Sha is a secure hashing algorithm with no keys, producing fixed-size hashes for integrity and certificate signing, and it exhibits an avalanche effect where small input changes yield large outputs.

Explore sha hashing features, including fixed-size hash outputs, a one-way function, collision resistance, and the avalanche effect, with applications in certificates and document signing.

Explore sha zero to sha three, comparing 160-bit and 256/512-bit hashes, fixed outputs, and the one-way function that prevents recovering input from the hash.

Explore hmac, a hash-based message authentication code that uses a shared secret key with a hash function like sha-2/3 to verify data integrity and support secure key exchange.

Explore how the sha algorithm pads input to 512-bit blocks, runs 64 rounds with a 256-bit initial hash value, and yields a 256-bit hash via a compression function.

Explore how cryptography algorithms are implemented in real systems, covering random number generation (pseudo and true RNGs), digital signatures, and the root of trust in secure boot.

Utilize rngs to generate unpredictable numbers from entropy sources such as thermal noise for key generation in symmetric, asymmetric, or HMAC algorithms used in SSL, TLS, SSH, Wi-Fi, and LTE.

Explain pseudo random number generators versus true random number generators, noting deterministic PRNGs with seed dependence and non-deterministic TRNGs based on physical sources for cryptographic key generation.

Explore true random number generator sources for cryptography, including thermal noise and phase noise, and learn how non-deterministic electron motion and oscillator jitter produce true randomness.

Discover how digital signatures ensure authenticity, integrity, and non-repudiation by signing with a private key and verifying with a public key using hashing and RSA.

This lecture explains generating a digital signature by hashing the message and encrypting the hash with the sender's private key, then verifying with the sender's public key via PKI.

Demonstrates signing and verification: hash the message, sign the hash with the private key, send the data and signature, then verify with the public key to ensure integrity.

Identify a root of trust as the secure starting point for a system, ensuring integrity, confidentiality, and authenticity before the operating system boots.

Enable a secure processing environment through root of trust modules, enabling secure boot, crypto modules (AES, RSA, SHA), key management, and a chain of trust for hardware, firmware, and apps.

Explore how secure boot enforces a root of trust to verify OS and firmware from the trusted OEM, establishing a chain of trust and protecting confidentiality.

Explore how the secure boot flow verifies bootloader and firmware images using RSA public keys and sha digests, decrypts signatures, and matches hashes to ensure trusted execution.

Compare symmetric and asymmetric cryptography, hashing, and digital signatures, and explain how key sizes, such as 128, 2048, and 256 bits, support secure storage, TLS, SSH, and secure boot.

Explore cryptology, cryptography, and cryptanalysis, and review AES, RSA, and SHA; learn key generation with a true random number generator, signing, verification, and root of trust for secure processing environment.