CompTIA Exam Prep - ITF+, A+, Network+, Security+, CySA+

Encryption protects data at rest and in transit. The awkward gap has always been data in use — to compute on something, you normally have to decrypt it first, which means the data is exposed in memory to whoever controls the machine. Homomorphic encryption lets you perform calculations directly on encrypted data and get an encrypted result that, once decrypted, is correct. The processor never sees the plaintext. The cloud provider never sees the plaintext. Only the key holder does, and only at the very end. A Concrete Example Suppose you encrypt the numbers 5 and 3. You send both ciphertexts to an untrusted server and ask it to add them. It performs an operation on the ciphertexts — it has no idea what values they represent — and returns a third ciphertext. You decrypt it and get 8. The server computed a correct answer to a question it could not read, about data it could not see. That is the whole idea, and it sounds impossible until you see that some encryption schemes pres...

The right to be forgotten — formally the right to erasure under Article 17 of the GDPR — allows an individual to require an organization to delete personal data it holds about them. It is one of several data subject rights that CompTIA groups under privacy, and it is the one with the most awkward technical consequences. The right is not absolute, and the hard part is not the policy. It is finding every copy. What the Right Actually Grants An individual can request erasure, and the organization must comply in defined circumstances: the data is no longer necessary for its original purpose; consent was the legal basis and has been withdrawn; the person objects and there is no overriding legitimate ground; the data was processed unlawfully; or erasure is required by law. Under GDPR the response deadline is one month , extendable by two further months for complex requests. When It Does Not Apply This is the part most often missed, and it is a likely exam point. Erasure can be ...