3DES = Run DES three times using 2 keys: DES (DES (DES, (m))) Same as DES if k1-k2 Why not just twice, 2DES? DES (DES (m)) Hint: Attackers could use "Known-Plaintext" Attack and "Meet-in-the-Middle Attack" to crack 2DES

3DES = Run DES three times using 2 keys: DES (DES (DES, (m))) Same as DES if k1-k2 Why not just twice, 2DES? DES (DES (m)) Hint: Attackers could use "Known-Plaintext" Attack and "Meet-in-the-Middle Attack" to crack 2DES

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

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Crack the following hashes obtained from a Windows system:Note: you'll want to utilize a wordlist attack with the rockyou.txt wordlist. Some passwords may need to apply rules or try common types of passwords used in a password spray attack. Tom:1004:8846F7EAEE8FB117AD06BDD830B7586C:::Stacy:1005:0AFAD548835E4B4B4C1A011ECA19F781::: Tom's password is: Stacy's password is:
BOB ALICE MD Нash Function message No Same? Yes discard Attacker Insecure Hash Function medium MD message Study the MD scheme that is shown in the scenario above, and answer the following question: This MD scenario doesn't solve the attack that is known as Man-in-the-middle attack with a false message. Explain how the MAC scheme if added into this scenario, can protect the communication from the so called Man-in-the-middle attack with false message.
Select each correct statement. If a cryptographic hash function is preimage resistant, then it is collision resistant. HMAC uses almost-universal hashing to produce an authentication tag. Wegman-Carter authentication uses a cryptographic hash to produce an authentication tag. If a cryptographic hash function is collision resistant, then it is preimage resistant. Fast cryptographic hashes are faster than fast almost-universal hashes.
Select all true statements about bloom filters in the box below ：A. If data A was never inserted to bloom filter, it is guaranteed that find(A) returns falseB. If data A was inserted to bloom filter, it is guaranteed that find(A) returns trueC. To detect malicious URLs, bloom filter is in general better than hash table because of its low false positive rate.D. For a fixed size bloom filter, using more hash functions can always help lower false positive rate.E. Assume the bloom filter is using the same hash functions, increasing the size of the bloom filtercan always help lower false positive rate.
blockchain is a collection ofrecords (called blocks), where each block links to the previous block using cryptography. Eachblock contains cryptographic hash, timestamp and data relevant to its application. Think ofit as a distributed ledger where instead of information being stored in a database it is storedon the blockchain. Some examples of solutions that use a blockchain at its core are:1. Cryptocurrencies (however, for this project you may NOT do a cryptocurrency)2. Smart contracts3. Trading4. Supply chain management5. Anti-counterfeiting6. Healthcare7. Domain names8. Proof of existence9. Voting10. and many others! Programming Language: Java The use of third-party libraries for primary functionally is strictly prohibited, however, third party libraries can be used for other functionality such as communications and visualisation (such as normal JavaFX, JFreeChart, GraphStream, JGraphT, Yworks, JUNG or JMonkey). The use of other data structures for auxiliary operations is…
This question relates to hash functions for block ciphers Block size = 4 bits Hash size = 4 bits Encryption function: Divide the key into two halves: LK and RK; Divide the plaintext into two halves: LT and RT; Then ciphertext= LC||RC where LC=LK XOR RT; and RC = RK XOR LT; where LC, RC, LT, and RT are each 2 bits; Plaintext and ciphertext are each 4 bits. g(H) = a 4-bit string that is equal to the complement of bits in H; For example, if H=A (Hexa) = 1010 (binary); then g(H)= 0101 H0 = Initial hash = C (in Hexa) Given message M: D9 (in Hexa); a. Determine the hash (in hexadecimal) of the message M using Martyas-Meyer-Oseas hash function b. Determine the hash (in hexadecimal) of the message M using Davis-Meyer hash function c. Determine the hash (in hexadecimal) of the message M using Migayuchi-Preneel hash function
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The hash code for Strings can be calculated once, at the time the String is created, which could potentially reduce its complexity.The precomputed value would be returned by subsequent calls to hashCode. This has the potential to be promising because a String's value never changes. How would you rate the effectiveness of such a procedure?
Cryptographic Data ObjectsB has just received the following message, which represents a cryptographic data object:{({(KPbB)KPrS mod KPbS}K1,{|(NB, NA, {{({K2}KPbB, NS)}(G1)KPrA mod NA}K1, {|{({G3}(KPbA)KPrS mod KPbS, G2)}K1|}KPrB)|}KPrA)}KBSThe following explains various terms in this object and some of the abbreviations used:• {M}K represents the encryption of some message/data M using the key K• {|M|}K represents the digital signing of some message/data M using the key K• NX represents a nonce (i.e. a fresh and possibly random number used once only) generatedby X• KpbX represents the public part of the key pair presumably owned by X• KprX represents the private part of the key pair presumably owned by X• KAB represents a symmetric key shared between A and B• K (or K1, K2, K3 etc.) represents some arbitrary key with no assumptions about its scope• M represents some alphanumeric/textual message with no assumptions• G1, G2, G3 etc. are prime numbersWhich of the following sets of keys,…
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I need help with this question, please. Parts A and B A.) Add the following numbers to an 11-entry hash table using linear probing to resolve collisions. Stop before adding an item that would result in α > 0.75. This means you might not use all the numbers. (Spoiler alert: you won't use them all.) 39 68 60 71 83 52 99 55 49 77 58 26 76 66 37 28 For the hash function, simply take the number mod the table size. In 11 blanks, write the number that would end up at that entry in the table. If there is no number at that location, write empty. B.) Add the following numbers to a 23-entry hash table using linear probing to resolve collisions. Stop before adding an item that would result in α > 0.75. This means you may not use all the numbers. 39 68 60 71 83 52 99 55 49 77 58 26 76 66 37 28 For the hash function, simply take the number mod the table size. In 23 blanks, write the number that would end up at that entry in the table. If there is no number at that location, write…
Network Security problem Q1] Consider the RSA encryption algorithm. Suppose that a malicious user intercepts the ciphertext C = 18 that is being sent to Alice. If Alice's public key PUa = {5,35) is known by the malicious user, show how the malicious user will recover the plaintext M? [Hint: find M=?] Note: C stands for Ciphertext, M stands for Message (Plaintext), PUa stand for Alice's public key.