Module 20 - Cryptography Flashcards
Which type of encryption uses 2 keys (Public & Private)
Asymmetric Encryption
Which type of encryption uses 1 shared secret key?
Symmetric Encryption
All of the following are types of Symmetric Encryption except:
a. AES
b. Twofish
c. RC4
d. DES
e. DSA
f. 3DES
g. Blowfish
e. DSA
Which of the following Symmetric Encryptions is a stream cipher?
a. AES
b. Twofish
c. RC4
d. DES
e. DSA
f. 3DES
g. Blowfish
c. RC4
What does symmetric encryption provide?
a. Confidentiality
b. Integrity
c. Authenticity
d. Availability
e. Non-Repudiation
a. Confidentiality
What is the #1 used symmetric encryption used today?
AES
What is the #1 asymmetric encryption used today?
RSA
All of the following are types of asymmetric encryption except?
a. RSA
b. DSA
c. DES
d. ECC
e. Diffie-Hellman
f. El Gamal
c. DES
Which of the following asymmetric encryptions is used for key enchange of symmetric keys?
a. RSA
b. DSA
c. DES
d. ECC
e. Diffie-Hellman
f. El Gamal
e. Diffie-Hellman
Which of the following asymmetric encryptions provides Non-Repudiation?
a. RSA
b. DSA
c. DES
d. ECC
e. Diffie-Hellman
f. El Gamal
Non repudiantion is a propriety of singatures.
All listed above provide signatures.
a. RSA
b. DSA
d. ECC
f. El Gamal
REF:https://en.wikipedia.org/wiki/Digital_signature#Some_digital_signature_algorithms
By default what is the encryption strength of AES?
a. 56 bit
b. 168 bit
c. 128 bit
d. 64 bit
e. 1 bit or 1 byte
c. 128 bit
What is the encryption strength of blowfish?
a. 56 bit
b. 168 bit
c. 128 bit
d. 64 bit
e. 1 bit or 1 byte
d. 64 bit
Comments: Defalut Key Sizes:
DES -> 56 bits
3DES->168 bits
AES-> 128 (also 192, 256)
RC4-> 64 bits
Blowfish->64 bits (also 32-448)
Twofish -> 128 bits
What is the encryption strength of RC4?
a. 56 bit
b. 168 bit
c. 128 bit
d. 64 bit
e. 1 bit or 1 byte
e. 1 bit or 1 byte
???
The tipical key size was 64 bits.
What is the encryption strength of DES?
a. 56 bit
b. 168 bit
c. 128 bit
d. 64 bit
e. 1 bit or 1 byte
a. 56 bit (error)
Is not a good ideia ask about a encryption strength because it is related with some diferents things. It depends on a lot of things:
- Key length
- Key management policies
- Nature of encryption algorithm (block size, stream cipher, etc)
From NIST.SP.800-57pt1r4.pdf: Section 5.3.1
Security strength (Also “bits of security”) A number associated with the amount of work (that is, the number of operations) that is required to break a cryptographic algorithm or system. In this Recommendation, the security strength is specified in bits and is a specific value from the set {80, 112, 128, 192, 256}.
“The strength of the cryptographic mechanisms (e.g., the algorithm, key length, block size, and mode of operation)”
One might expect that 3TDEA would provide 56 × 3 = 168 bits of strength. However, there is an attack on 3TDEA that reduces the strength to the work that would be involved in exhausting a 112-bit key. For 2TDEA, if exhaustion were the best attack, then the strength of 2TDEA would be 56 × 2 = 112 bits
But sometimes, when someone is asking about the encryption strength, is talking about the key length or the key strength.
What is the encryption strength of twofish?
a. 56 bit
b. 168 bit
c. 128 bit
d. 64 bit
e. 1 bit or 1 byte
c. 128 bit
What is the encryption strength of 3DES?
a. 56 bit
b. 168 bit
c. 128 bit
d. 64 bit
e. 1 bit or 1 byte
b. 168
(key size)
_____ is a set of hardware, software, people, policies, and procedures required to create, manage, distribute, use, store, and revoke digital certificates.
PKI (Public Key Infrastructure)
Public Key Infrastructure (PKI):
- Issues and verifies digital certificates.
- Keeps the private key, and gives the company the public key for them to publish.
a. Registration Authority (RA)
b. Validation Authority (VA)
c. Certificate Authority (CA)
d. Digital Certificate
c. Certificate Authority (CA)
Public Key Infrastructure (PKI):
- Acts as the verifier for the certificate authority.
- Intermediary between the company and CA.
-
Cannot Issue Certificates
a. Registration Authority (RA)
b. Validation Authority (VA)
c. Certificate Authority (CA)
d. Digital Certificate
a. Registration Authority (RA)
Disk Encryption:
Disk encryption protects ___________ of the data stored on disk by converting it into an unreadable code using disk encryption software or hardware.
a. Protection
b. Availability
c. Confidentiality
d. Encryption
c. Confidentiality
Cryptanalysis:
- Contains many non-repeating groups of letters or number keys, which are chosen randomly.
- Only usable once activated, not before and will only be usable for a determined amount of time.
a. Brute-Force
b. Frequency Analysis
c. Trickery and Deceit
d. One-Time Pad
d. One-Time Pad
Cryptanalysis:
Extraction of cryptographic secrets (e.g. the password to an encrypted file) from a person by coercion or torture.
a. Chosen-Ciphertext Attack
b. Rubber Hose Attack
c. Chosen-Key Attack
d. Timing Attack
e. Man-in-the-Middle Attack
b. Rubber Hose Attack
________ encryption uses the same key for encryption as it does for decryption.
Symmetric
__________ encryption uses different encryption keys for enctyption and decryption.
Asymmetric
All of the following are email encryptions except?
a. TLS
b. S/MIME
c. PGP
d. GPG.
a. TLS
Comments
- TLS is used to cripty http trafic,
- GPG is a GnuPG, a complete and free implementation of the OpenPGP standard
