When a web client requests access to protected resources on a web server, demonstrate the implementation of native authentication and authorisation services. Layered protocols have two significant proponents: Provide specific evidence to support your assertions.

Comparing cypher block chaining to cypher feedback mode in terms of the number of encryption operations necessary to transport a large file, cypher block chaining is more efficient than cypher feedback mode. Which one is more efficient, and how much more so?

7. Consider a one-way authentication technique based on asymmetric encryption: A→B: IDA BA: E(PU, R₂) A-B: R₂ a. Explain the protocol. b. What type of attack is this protocol susceptible to?

The S/MIME for email specification allows for encryption before signing or signing and encrypting. Each has different security properties. PGP specifies that one should sign and then encrypt. Use the Cryptographic protocol shape analyzer(CPSA) tool to determine what attacks are possible against each approach or if either are secure. Is PGP correct to specify only one way to perform authentication and confidentiality? Model the protocols, specified below for your convenience, and identify any attacks against the protocols or if the messages are securely received (authenticated and confidential). Determine if you receive an authentic message, was it intended for you or someone else or if when you receive the message, is it authentic. (For extra credit: If you identify any attacks, can you change the protocol to prevent the attacks?)   For the following descriptions, M is the message, K is a freshly chosen symmetric key, PubK(N) is the public key of N, and PrivK(N) is the private key of…

Explain this more  What is the tradeoff however with each pass?   Answer here: Minimum 200 words addressing tradeoffs.   I’m understanding this question, in the way that if we apply ciphers multiple times using the same key then it will either completely negate encryption an even number of encryptions attempts or only apply it once for an odd number of encryption attempts. If we have a secure password, then we can focus on protocols and systems instead of passwords

Show protocols for both weak and strong PUFs and how they can be used toprovide authenticity properties in IoT systems.

2.  Recall the concept of Physically Unclonable Functions, which are an importantcomponent of hardware based security. Here is a simple scenario and simple protocol usingPUFs for authenticating a tag. In the protocol below, the Reader stores ALL possiblecombinations of Challenge-Response pairs for every tag it needs to authenticate. Duringauthentication, the Reader broadcasts the ID of the tag, and a greeting (Gn ). Every tag maysee this message, but only the one with the right ID will process the message. The right tagwith the ID in the message will then feed the greeting to its PUF and compute the responseSn. The response is then sent to the Reader. This should be clear from the Figure below. Forthe next round of authenticating the same Tag, the process repeats with a new Greeting(G n+1 ). Since the Reader has the responses, authentication is straightforward. Recall thatChallenges and Responses are typically 128 or 256 bit strings for RFIDs.From the protocol, and class, it should be…

Alice and Bob use the following challenge –response authentication scheme based   on digital signature. To avoid chosen text attack, they decide that Alice will sign R=  RA   XOR RB, where RA is chosen by Alice and RB is chosen by Bob. They work out  following  protocol: Alice >Bob : Alice, RA Bob >Alice : RB Alice >Bob : S (KRA, {R})            KRA is the private key of Alice. Bob verifies Alice’s signature on R to authenticate              Alice.   An adversary wants Alice to sign on text RT chosen by him. How does he               exploit the   protocol for achieving this goal?   please the explain the answer in short

True or False  1. authentication exchange is the use of a trusted third party to assure certain properties of a data exchange 2. a loss of integrity is the unauthorized modification or destruction of information 3. the denial of service prevents or inhibits the normal use or management of communication facilities

What are the potential limitations of Electronic Code Book (ECB)? If one ciphertext block is corrupted during the transmission, all subsequent ciphertext blocks cannot be decrypted unless until corrupted block is successfully retransmitted. Repetitive information contained in the plaintext may show in the ciphertext, if aligned with blocks. If the same message (e.g., an SSN) is encrypted (with the same key) and sent twice, their ciphertexts are the same. It needs an initialization vector to operate.