SEAL is a stream cipher that uses a 160-bit encryption key. It is a symmetric
encryption algorithm that has a lower impact on the CPU resources compared to other software-
based algorithms, such as software-based DES, 3DES, and AES.
2. Which statement is a feature of HMAC?
A. HMAC uses protocols such as SSL or TLS to provide session layer confidentiality.
B. HMAC uses a secret key as input to the hash function, adding authentication to integrity assurance.
C. HMAC is based on the RSA hash function.
D. HMAC uses a secret key that is only known to the sender and defeats man-in-the-middle attacks.
A keyed-hash message authentication code (HMAC or KHMAC) is a type of
message authentication code (MAC). HMACs use an additional secret key as input to the hash
function, adding authentication to data integrity assurance.
3. Which requirement of secure communications is ensured by the implementation of MD5 or SHA hash generating algorithms?
Integrity is ensured by implementing either MD5 or SHA hash generating
algorithms. Many modern networks ensure authentication with protocols, such as HMAC. Data
confidentiality is ensured through symmetric encryption algorithms, including DES, 3DES, and
AES. Data confidentiality can also be ensured using asymmetric algorithms, including RSA and
4. Which algorithm can ensure data confidentiality?
To address the interoperability of different PKI vendors, IETF published the
Internet X.509 Public Key Infrastructure Certificate Policy and Certification Practices
Framework (RFC 2527). The standard defines the format of a digital certificate.
7. What are two symmetric encryption algorithms? (Choose two.)6. Which protocol is an IETF standard that defines the PKI digital certificate format?
The higher the certificate number, the more trustworthy the certificate. Class 1
certificates are for individuals, with a focus on email verification. An enterprise can act as its
own CA and implement PKI for internal use. In that situation, the vendor can issue certificates as
needed for various purposes.