Asymmetric CryptoSystem Quiz! Trivia

The private key of a user should not appear on the digital certificate because the private key is meant to be kept secret and known only to the user. It is used for encryption and decryption processes, and if it were to appear on the digital certificate, it would compromise the security of the user's data and communications. Therefore, it is important to keep the private key confidential and separate from the digital certificate.

Public key encryption/decryption is not preferred because it is slow, hardware/software intensive, and has a high computational load. These factors make it less efficient and practical for certain applications.

CRL stands for Certificate Revocation List. A Certificate Revocation List is a list of digital certificates that have been revoked by the issuing Certificate Authority (CA) before their expiration date. This list is used to check the validity of a digital certificate and ensure that it has not been revoked, ensuring the security and trustworthiness of the certificate.

It is desirable to revoke a certificate before it expires because all of the mentioned reasons are valid. Revoking a certificate ensures that the user is no longer certified by the Certificate Authority (CA), which is important if the user's certification is no longer valid or trustworthy. Additionally, revoking a certificate is necessary if the CA's certificate is assumed to be compromised or if the user's private key is assumed to be compromised. Revoking the certificate in these cases helps to maintain the security and integrity of the certificate system.

A digital certificate is trusted because it contains the CA's signature. The CA (Certificate Authority) is a trusted entity that verifies the identity of the certificate owner and signs the certificate to confirm its authenticity. By including the CA's signature, the digital certificate ensures that it has been issued by a trusted authority, providing assurance that the certificate and its associated public key can be trusted for secure communication and authentication purposes.

The property of 'p' and 'q' in the RSA algorithm is that they should be prime. This is because the security of the RSA algorithm relies on the difficulty of factoring large composite numbers into their prime factors. By selecting 'p' and 'q' as prime numbers, it ensures that the factorization process is more challenging and helps to protect the encryption keys.

The Serial Modifier is not an element/field of X.509 certificates. X.509 certificates contain fields such as Issuer Name, Issuer Unique Identifier, and Signature, which are used for identifying and verifying the certificate. However, the Serial Modifier is not a recognized field in X.509 certificates.

The given question asks to perform encryption using RSA on the given plaintext (PT) and find the ciphertext (CT). The values of p and q are provided as 3 and 11 respectively, and the value of e is given as 3. The plaintext (M) is given as 5. To find the ciphertext, we need to calculate M^e mod (p*q), which is equivalent to 5^3 mod (3*11). Simplifying this expression, we get 125 mod 33, which is equal to 26. Therefore, the ciphertext (CT) is 26.

A set is considered superincreasing if each element in the set is greater than the sum of all the previous elements. In this case, the set {1, 2, 3, 9, 10, and 24} is not superincreasing because the last element, 24, is not greater than the sum of all the previous elements (1 + 2 + 3 + 9 + 10 = 25). Therefore, the correct answer is False.

In Merkle-Hellman Cryptosystem, the easy knapsack becomes the private key and the hard knapsack becomes the public key.

To verify a digital signature, we need the sender's public key. The sender uses their private key to create the digital signature, which is a unique cryptographic representation of the message. The receiver can then use the sender's public key to verify the digital signature and ensure that the message has not been tampered with. The public key is used for verification purposes, while the private key is kept secret by the sender to maintain the integrity and authenticity of the digital signature.

In digital signature, there is a one-to-one relationship between the signature and the message. This means that a unique signature is generated for each specific message. The digital signature is created using the sender's private key and can only be decrypted using the corresponding public key. This ensures that the signature is unique to the message and verifies the authenticity and integrity of the message.

The given ciphertext is 38, and the corresponding plaintext code is 01101. This means that in the Knapsack {1 6 8 15 24}, the items with values 6, 15, and 24 were selected to form the ciphertext. By converting the binary representation of the selected items into plaintext, we get the code 01101.

When creating a digital envelope, the one-time session key is encrypted with the receiver's public key. This ensures that only the intended receiver, who possesses the corresponding private key, can decrypt the session key and access the encrypted message. The use of a one-time session key adds an extra layer of security as it is only used for a single communication session and then discarded, reducing the risk of key compromise and unauthorized access to the message.

A Registration Authority can issue digital certificates. In the context of public key infrastructure (PKI), a Registration Authority (RA) is an entity responsible for verifying the identities of individuals or organizations requesting digital certificates. After performing the necessary verification steps, the RA can approve or reject the certificate request. If approved, the Certificate Authority (CA), which works closely with the RA, will issue the digital certificate. The digital certificate is a critical component in securing communications and transactions by verifying the identity of users, devices, or servers.