Let's say you are generating RSA keys and you choose p=19, q=23 and encryption exponent e=5. What value d do you choose for the decryption exponent? Some useful queries might be things like "gcd(50,35)" or "inverse of 7 mod 13"

Samantha uses DSA with public parameters (p, q, g) = (22531, 751, 4488). She chooses the secret signing key a = 674. (b) Samantha signs the document D = 244 using the random element k = 574. What is the signature?

In this problem we explore the relationship between password length and cryptographic security. Suppose a password consists of 77 ASCII characters. You can review the ASCII characters here.. Exactly 27=12827=128 of these codes are for printable characters; we will assume every character in the password is printable. What is the size of the keyspace that consists of passwords of this form?What is the equivalent key length in bits?  Assuming that you could check one password every 10−810−8 seconds, what is the worst case running time for cracking this password by brute force search (in days)? Now assume that the user used only 3131 characters from the keyboard. What is the key length in bits in this case?  How many days, in the worst case, would it take to break this weaker password? You can't round to the nearest day here -- be as exact as possible.  Supposing you used only 3131 characters, how long is the shortest password that achieves 252252 bits of security?

Decode the number using the given private key. Decode the number M = 15 using the private key d = 53 and n = 77. Assume you are decoding the number using the RSA cryptosystem. Note: You can use the Modular Exponentiation calculator to help with the calculation. a 63 (mod 77), decoded number = 63 b 64 (mod 77), decoded number = 64 C 65 (mod 77), decoded number = 65 d. 66 (mod 77), decoded number = 66

Suppose your RSA public key is PK: {n, e} = {13861, 37}. Your friend sends you a ciphertext C = 9908. But unfortunately you have forgotten your private key, now you have to crack it yourself.a) Write down a possible condition of factors p and q.p= q=b) What is your private key SK: {d}?d=c) What is the plaintext of your friend’s message?The plaintext M =d) Suppose the plaintext M is a 12-digit number consisting of a prefix “19” and 1234567890. What is the corresponding ciphertext? Since M is greater than n, you only need to encrypt four digits at a time. Ignore redundant zeros. e.g., 0001 = 1. The result should contain three integers.The ciphertext C0 =

Show, using worked out examples, that for RSA, PB(PR(M))=M and  PR(PB(M))=M, where PB, PR and M, respectively are the public key, the private key, and the plaintext. Design the keys using prime numbers 11 and 17.

In an RSA system, the public key (n,e) of a given user is (323, 11). 1. What is the value of the exponent in the private key (n, d), of this user? 2. Suppose you want to send this user the message m = 45, write down the expression to generate the ciphertext for this message. 3. Suppose that your ciphertext, c, is 5, write down the expression to generate the plaintext matching this ciphertext. 4. Can you encrypt the message m=322 with this public key? O a. Yes O b. No

Are there any differences between a Key Derivation Function (KDF) and the family of secure hash functions known as the SHA family? In order to make your message absolutely clear, include as much information as is necessary.