8
votes
1answer
81 views

Is it possible to test implementation for side-channel attacks?

When it comes to implementing cryptographic algorithms, there seems to be a big focus on the difficulty of doing so without introducing the potential for side channel attacks and the knowledge ...
0
votes
0answers
53 views

Explanation of cryptographic terminology for newbies [on hold]

I feel like I'm making a mountain out of a molehill here, but I have (what should be) a relatively simple project, but the terminology used all over the Internet is either too simple or too difficult ...
0
votes
0answers
12 views

Can someone help me decipher this? [closed]

I have absolutely no idea what this is or how to decipher it. Could you either do it... or help me learn how to? ...
1
vote
3answers
137 views

Any benefit to writing a message as a mix of 2 languages before encryption?

For example, imagine a message that is a mix of Japanese and English words; Japanese in unicode, English in ASCII. Japanese doesn't use spaces between words. The sentence structures, anything ...
0
votes
0answers
39 views

Found weil pairing. Index Calculus method on the results of weil pairing

Consider Elliptic curve with p = 59, A = 1, B= 0, P = (25,30) and Q=(35,31). So I tried to solve this using MOV attack. The torsion point for them E[5] is R(-25,30i) where is sqroot -1 Chosen two ...
3
votes
1answer
64 views

Parameterizing adversaries with security parameters

In many cryptographic games, the adversary doesn't seem to be parameterized by the security parameter.‡ Are such games equivalent to variants in which the adversary is parameterized by the security ...
11
votes
2answers
947 views

Can any MAC be used as a KDF?

First, let me clarify what I mean with a Key Derivation Function (KDF). I'm interested in KDFs that take an $n$-bit symmetric master key and some diversification data of arbitrary length as input and ...
3
votes
2answers
92 views

Importance of round complexity in determining the efficiency of an MPC protocol

Literature has different ways of specifying complexity of an MPC protocol: computation complexity that measures the number of (assumed primitive) operations performed by all the parties; ...
0
votes
0answers
33 views

Dependency of cryptographic protocols on cryptography primitives

To what extent depend cryptographic protocols on cryptographic primitives? Are there cryptographic protocols that can only be implemented with certain cryptographic primitives? If the answer is yes, ...
0
votes
0answers
52 views

Why is RSA still being used? [duplicate]

In hybrid encrytion, I still see that some site's use RSA in their https connection, so now I wonder, why do they not use ECC instead of RSA, ECC requires less computational power and encrypt's and ...
3
votes
0answers
22 views

How to decrypt the below encrypted messages? [on hold]

My friend was experimenting with the encryption methods (self-made) to encrypt text using ASCII map. He wanted to try this idea whether this encryption can be broken and so shared an encrypted text ...
2
votes
1answer
533 views

Decrypting a blowfish cipher with three keys

Disclaimer: I'm pretty new to cryptography and I don't have a strong mathematical background. I apologize in advance if I missed something blatantly obvious. I participated in a security CTF this ...
-3
votes
0answers
75 views

Public-key Cryptography: I need a technical answer [closed]

So, I already understand the point of Public-key cryptography, and how it's supposed to work. I understand the basics, and I've seen way to many diagrams. What I haven't seen enough of, however, is ...
2
votes
3answers
63 views

Is there a method/protocol to validate a self-signed certificate by comparing a shortened hash?

I'm working on a solution where an iPad should connect to a server software running on a laptop using TLS with a self-signed certificate that was automatically generated on the laptop during the ...
0
votes
1answer
63 views

Given a prime exponent e and a prime number n, find b, where b^e = 1 mod n

Can anyone help me with the following problem. Given a prime exponent $e$ and a prime number $n$, find $b$, where $b^e \equiv 1 \bmod n \land b > 1$. For example, $b^5 \equiv 1 \bmod 11$ how to ...
-2
votes
1answer
46 views

In Shamir's (t, n) secret sharing scheme why don't use infinite field? [duplicate]

Well, we use finite fields to select shares. What happened if we use infinite fields.then will the scheme be vulnerable? Easy to break? Or share generation and reconstruction will be difficult? ...
1
vote
1answer
36 views

Given C is a code of length n. Containing M code-words with a distance d

I'm studying for my exam and came across this question below. I don't understand how to get $d$. I get $C$ is a code of length $n$. Containing $M$ code-words with a distance $d$. $(n,M,d)$ But how ...
2
votes
1answer
122 views

How does DH work when combined with ECC or RSA?

I know that Diffie-Hellman is used to create keys in a secure way over an insecure channel. But there is one thing which I cannot understand: I see that a lot of sites use ECC or RSA alongside DH. ...
5
votes
1answer
50 views

Binary format of encrypted PGP private key?

Short Version of the Question: I would like to remove any predictable information from an encrypted private keys binary representation. Does anyone have a hint where the binary format for encrypted ...
3
votes
1answer
112 views

Is the use of AES in LoRaWAN correct?

I'm reading about LoRaWAN (specification). This network protocol has a particular way to encrypt data, detailed in the part 4.3.3.1. Here is a recap of how the encryption work, as I understood it. ...
2
votes
1answer
37 views

Find an example of a lattice such that LLL algorithm can't find the shortest vector of the lattice, satisfying

I want to find an example of a basis of a lattice of dimension $n$ such that LLL algorithm can't find the shortest vector of the lattice, and such that the shortest vector of this lattice, say $b=...
0
votes
0answers
27 views

Password manager that uses a mix of long and short key derivation functions

I was reading "A Convenient Method for Securely Managing Passwords, Halderman et al., 2005". In short, the authors say to do the following: ...
4
votes
0answers
36 views

Quantum complexity of LWE

As per my understanding LWE is quantum secure because there is no known quantum algorithm to solve LWE in polynomial time. Due to the reductions given by Regev et al. If there is any algorithm that ...
2
votes
0answers
58 views

Are analog quantum computers a threat to RSA and DLP?

We already know that D-WAVE's "quantum computers" can't really run the Shor's algorithm, because the way they're built doesn't qualify them as universal quantum computers. Now researchers actually ...
-1
votes
0answers
26 views

Identify a hash which was already seen? [closed]

I have a question. In our group we are processing a large number of datasets. Each one is identified by its hash (pseudo-random ASCII string). We are currently looking for a way to tell if we already ...
3
votes
1answer
84 views

Salting Hash stored on RFID tag?

In my application, I am trying to prevent counterfeit widgets from being used on our gadgets; think HP ink-cartridges. I will be doing such with UHF RFID tags embedded in the widgets. Unfortunately, ...
1
vote
0answers
12 views

how to create and use sub keys with PGP? [migrated]

let's say i wish to have forward secrecy with PGP, that requires me to create multiple sub keys to be used and destroyed accordingly, how should i do it?
0
votes
0answers
55 views

Security Proof in Fuzzy Identity Based Encryption?

Been having a great deal of difficulty understanding the use of simulators to prove security of ABE schemes so I though I would start from the first ABE paper (Fuzzy Identity Based Encryption) to try ...
1
vote
1answer
25 views

Conditional probability with Vigenere Cipher given specific plaintexts and key sizes

Apologies if this should be in the Mathematics stack exchange, I just ask it here because the context is cryptography. Here is the question that I seemingly cannot get correct: Consider the ...
3
votes
1answer
33 views

Conditions for Perfect Secrecy with the Vigenere Cipher

Please forgive my ignorance here as I'm far from a math major and I've never looked into cryptography before so if this seems stupid - it probably is. There is a question in a quiz I'm attempting that ...
-1
votes
0answers
20 views

How do we compare two hash functions / cryptographic functions [closed]

I know what hash functions are but as my research project I am comparing two cryptographic algorithms so I am a bit confused about on what bases should I compare the two algorithms as these are ...
0
votes
1answer
59 views

Questions about length key of RSA 2048 bit

I use putty gen to generate RSA key, I choose length of key is 2048 bit, it generate public key: ...
3
votes
1answer
64 views

proof of correctness Ring-LWE cryptosystem

I've been studying Ring-LWE based crytposystems such as the one in this paper, but I can't seem to find/come up with a proof of correctness for this particular scheme. The encryption goes as follows: ...
-1
votes
0answers
23 views

Counter-Mode Message Authentication Code [duplicate]

Excuse my naivety,I don't know much about crypto. But I've been wondering, couldn't counter-mode be used for MAC just like CBC in CBC-MAC, assuming nonce for the counter is not repeated? Am I missing ...
-1
votes
0answers
14 views

.cyt file extension, don't know what software to use to open this file type [closed]

I encrypted some zip files in 2010 and found them recently on my hard drive, but I have no idea what software I used to encrypt them so now I cannot open the files, which is very annoying. The files ...
2
votes
1answer
97 views

Forgery attack against Textbook RSA with simple redundancy

I know how to forge vanilla Textbook RSA message signatures (easy). I've learnt that by adding a good redundancy to the message, it cannot be forged anymore. How can one add redundancy so that the ...
0
votes
0answers
22 views

Diffie-Hellman combined with DSA/RSA

we have learned Diffie-Hellman, RSA and DSA (Digital Signature Algorithm) in university. Because DH is vulnerable of Man-in-the-Middle we had the task to program the DH combined with RSA to protect ...
1
vote
1answer
27 views

Can I use the Sequence Number as the (implicit) IV in AES-GCM IPsec?

The RFC https://tools.ietf.org/html/rfc4106#page-5 states that, under AES-GCM IPsec, each packet is expanded by 8 bytes for the IV and up to 16 bytes for the ICV. Why? Since we already have a ...
-1
votes
0answers
56 views

NSA Suite B revoked [closed]

NSA Suite B was formerly documented in CNSSP-15 "National Information Assurance Policy on the Use of Public Standards for the Secure Sharing of Information Among National Security Systems". NSA has ...
3
votes
1answer
78 views

tripartite diffie hellman with Weil pairing

I try to understand how the tripartite Diffie-Hellman key exchange works. I read Joux's paper for this: https://www.semanticscholar.org/paper/A-One-Round-Protocol-for-Tripartite-Diffie-Hellman-Joux/...
5
votes
1answer
66 views

What is the most efficient attack on NTRU?

So, I got how finding the private key is equivalent to resolving the SVP. I also understood that the LLL algorithm can only be used in small dimensions. Now, I wonder what is the most efficient attack ...
3
votes
1answer
104 views

Change initial hash value of SHA512/t

Fips 180-4 defines under 5.3.6 how to calculate initial hash values for SHA512/t for a given value t. Can someone explain me how the t actually affects the outcome of the procedure (which, as far as I ...
4
votes
1answer
662 views

What does this notation stand for when describing a code?

This code has appeared in some online course material. I understand the $(5, 4, 3)$ refers to (length, num codewords, distance) but no explanation of the $Z_2^5$ notation is given: One $(5,4,3)$ ...
0
votes
1answer
33 views

factorization of an integer $N$ that is in special format

Suppose $p_0$ and $q_0$ are known prime numbers and define $p_i$ and $q_i$ as follows: $$p_{i+1} = next\_prime(p_i^2 + q_i^2), \qquad i \ge 0$$ and $$q_{i+1} = next\_prime(2p_iq_i), \qquad i \ge 0$$ ...
1
vote
0answers
31 views

Are public key and private key exchangeable? [duplicate]

If I get a key pair from RSA algorithm, can I make Private-Key public, and keep Public-Key secret without breaking the security of encryption and signature?
5
votes
1answer
79 views

Nonce for AES GCM to prevent replay attacks

I am wanting to encrypt a message with a pre shared key that uses AES GCM from the OpenSSL library to do so. I generate my key for the AES crypto via hashing my pre shared key with a salt using the <...

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