WGU Introduction-to-Cryptography Exam With Confidence Using Practice Dumps

The string format $2a$08$... is a well-known identifier for the bcrypt password hashing scheme. In common password-hash notation, the prefix indicates the algorithm and parameters: “$2a$” denotes bcrypt (version 2a), and “08” indicates the cost factor (work factor) controlling how computationally expensive hashing is. bcrypt is designed specifically for password storage: it includes a built-in salt and is intentionally slow and adaptive, making brute-force and GPU attacks far more expensive than fast general-purpose hashes like MD5 or SHA-512. NTLM and MD5 are obsolete for secure password storage due to speed and known weaknesses. SHA-512, while cryptographically strong as a hash, is still too fast for password hashing unless used in a dedicated password-hashing construction (e.g., PBKDF2, scrypt, Argon2) with appropriate parameters and salts. Since the given hash clearly matches bcrypt’s encoding, the correct algorithm is bcrypt, which incorporates salting and cost-based key stretching as part of its design.

AES supports three standardized key sizes: 128, 192, and 256 bits, with a fixed block size of 128 bits. The maximum of these supported key sizes is 256 bits (AES-256). Key size affects resistance to brute-force key search: larger keys exponentially increase the search space. In practice, AES-128 is already considered strong against brute force with contemporary computing capabilities, while AES-256 is often chosen for compliance requirements, conservative security margins, or to hedge against future advances. AES-512 is not part of the AES standard; if 512-bit keys are desired, systems typically use different constructions (like using AES-256 in certain key-derivation or wrapping schemes) rather than changing AES itself. Therefore, the correct maximum supported AES key size is 256 bits.

HMAC (Hash-based Message Authentication Code) is a standard mechanism used to verify both integrity and authenticity of a message when two parties share a secret key. It combines a cryptographic hash function (such as SHA-256) with a secret key in a structured way that resists common attacks on naïve keyed-hash constructions. The sender computes an HMAC tag over the message and transmits the message plus tag. The receiver recomputes the HMAC using the same shared secret key and compares the result; if the tag matches, the receiver can be confident the message was not modified in transit and that it came from someone who knows the shared key. AES is an encryption algorithm primarily providing confidentiality; it can provide integrity only when used in authenticated modes (e.g., GCM) but “AES” alone is not the integrity component. An IV helps randomize encryption but does not validate integrity. TKIP is a legacy WLAN protocol component, not the general integrity verifier. Therefore, the correct component for verifying message integrity among the options is HMAC.