What does "2FA" stand for in cybersecurity?

(a)  

What does the "S" in HTTPS stand for?

(a)  

Decrypt the following Caesar cipher message: KLFUHZ

(a)  

Bob received a secret message: GSRH RH Z HVXIVG

(a)  

A secret message encrypted using a repeating key method:

Ciphertext: OPXTLHJAW

Key: SHIP

(a)  

Caesar Cipher Challenge (Pangram):

.

WKH LPSRVWRU LV LQ WKH PDLQ VKLS

(a)  

Number Cipher: Ciphertext numbers: 6 0 12 4 18

(a)  

A cyber-security analyst finds an RSA public key:

n = 323, e = 5

Find d such that:

5d ≡ 1 (mod φ(n))

_{Follow these steps to help him:}

_{Factor n into two primes p and q.}

_{Compute φ(n) = (p - 1)(q - 1).}

_{(Hint: use 5d = 1 + kφ(n) and try small k = 1, 2, 3, …)}

(a)  

Vigenère Cipher:

Ciphertext: DHOTBCAUB

Key: LEMON

(a)