WGU Introduction-to-Cryptography Exam Dumps

RC4 is unique among the RC family listed because it is a stream cipher. It generates a pseudorandom keystream and encrypts data by XORing that keystream with plaintext bytes (and decryption is the same XOR operation). This differs from RC5 and RC6, which are block ciphers: they encrypt fixed-size blocks of data through multiple rounds of operations (such as modular addition, XOR, and rotations) using a secret key. The stream-cipher design means RC4 historically fit protocols where data arrives continuously (e.g., early wireless and web encryption) and where simple, fast software implementation was desired. However, stream ciphers demand careful handling of nonces/IVs to avoid keystream reuse; reuse can catastrophically leak plaintext relationships. RC4 also has well-documented statistical biases in its keystream, leading to practical attacks in protocols like WEP and later concerns in TLS, which is why RC4 has been deprecated in modern security standards. Still, from a classification standpoint, ''stream'' is the distinguishing characteristic versus RC5/RC6 being block ciphers.

Data integrity means ensuring that information has not been modified without authorization. Digital signatures are a core cryptographic technique that provides integrity by binding a message (typically its hash) to the signer's private key. The signer creates a signature over the message digest; the verifier checks it with the signer's public key and recomputes the digest. Any change to the message alters the digest and causes verification to fail, revealing tampering. Digital signatures also support authenticity (verifying the signer) and can contribute to nonrepudiation under proper key-management and policy controls, but integrity is a primary guarantee they deliver. ''Authentication'' is broader and can be achieved by other means, but it is not as directly tied to integrity as signatures in this option set. ''Non-repudiation'' is an outcome/goal rather than a standalone integrity technique. ''Steganography'' hides the existence of data and does not inherently protect integrity. Therefore, among these options, digital signatures are the best cryptographic technique for ensuring data integrity.

A block cipher mode of operation defines how a block cipher (such as AES) is applied to data longer than a single block, and how blocks are linked (or not linked) to provide certain security properties. ECB (Electronic Codebook) is one of the canonical block cipher modes: it encrypts each plaintext block independently using the same key. While ECB is generally discouraged because it leaks patterns (identical plaintext blocks produce identical ciphertext blocks), it is still a valid and historically important mode of operation and is often used as a teaching example of what not to do for structured data. In contrast, SHA-256 is a hash function (one-way digest) and not a mode for block ciphers. DSA is a digital signature algorithm and provides authenticity/integrity, not encryption mode behavior. RSA is an asymmetric cryptosystem, not a block cipher mode. Therefore, among the options, ECB is the correct example of a block cipher mode of operation.

A cryptography framework provides a consistent, repeatable way to select, deploy, and manage cryptographic controls across an organization. Its key benefit is structure: it defines approved algorithms and key sizes, acceptable modes of operation, key management rules (generation, storage, rotation, revocation, backup), certificate handling, and secure protocol configurations (e.g., TLS settings). This reduces ad hoc implementations that often lead to vulnerabilities such as weak ciphers, key reuse, improper randomness, or missing integrity protections. A framework also clarifies roles and processes---who can access keys, how secrets are audited, and how exceptions are handled---improving governance and operational reliability. Importantly, it does not guarantee perfect security; no framework can eliminate all risk, and secure outcomes still depend on correct implementation, monitoring, and maintenance. It also does not eliminate the need for training; human error is a major source of crypto misconfiguration. While frameworks help with compliance, they are not solely about regulation; they are about sound security engineering and lifecycle management. Therefore, the primary benefit is providing a structured approach to implementing encryption practices.

The ''Issued'' stage in a certificate lifecycle indicates that the certificate has been generated and signed by the issuing CA and is now valid for use (subject to validity dates, policy constraints, and revocation status). At this point, the operational focus shifts from creating the certificate to making it available to the subject and relying parties. ''Distribution'' is the lifecycle activity most directly associated with an issued certificate: installing it on servers or endpoints, provisioning it into keystores, publishing it to directories if required, and ensuring the chain (intermediates) is accessible for validation. By contrast, ''Creation'' is earlier in the process (key generation, CSR creation, identity validation, issuance/signing). ''Key recovery'' and ''key archiving'' relate to private key management and escrow policies (often for encryption keys, not signing keys), and are governed by organizational policy and key management systems rather than the certificate's issued state itself. A certificate can be distributed after issuance regardless of whether any key escrow features exist. Therefore, the operation that fits the certificate's ''Issued'' stage best is distribution of the issued credential for operational use.