3
votes
1answer
80 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
53 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
24 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
31 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 [on hold]

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
57 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 [on hold]

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
68 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
21 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
55 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
74 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
65 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
98 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
31 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
75 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 <...
0
votes
0answers
24 views

What is the best approaches to find the type of a Cipher / Encryption? [duplicate]

There are many known and unknown encoding and encryption types / algorithms. When the algorithm is known, then at least it gives some direction or approach on what to do next to obtain the plaintext ...
3
votes
0answers
133 views

Inverting a candidate one way function

Let $w = a_0 \cdot a_1 \cdots a_{n-1} $ be a word from $ \{0,1\}^n $, $|w| = n$ Let $m = \sum_{i=0}^{n-1}{ a_i \cdot 2 ^ {n-1-i} } $ be the corresponding binary number constructed from the word. Let ...
5
votes
1answer
63 views

Are there any high level memory-hard PBKDF constructions?

The PBKDF2 construction from PKCS #5 v2 has the convenient feature that it can be implemented using only standard interchangeable cryptographic primitives. Specifically, it only requires the ...
-2
votes
0answers
15 views

How does the input of (0..11) (512 bit) impact on the SHA-1 algorithm [duplicate]

If my H0(A0=B0=...=000hex) I think i wouldnt´t change anything and and my output for Round 1 would be K1 = 5A827999(hex)
0
votes
0answers
26 views

Error Detection/Correction Code-Then-Encrypt

I've just studied about the error correction schemes and encryption. First rule when using EDC/ECC is to first encrypt and then calculate them, and the major motivation we were told is that "EDC/ECC ...
0
votes
1answer
26 views

Secure Cipher Suites supported by JDK versions [closed]

I'm a n00b to cryptography. I've been searching through oracle's java docs, ssl labs, googling and more googling attempting to find an up to date list of cipher suites considered secure for the ...
4
votes
1answer
60 views

What is the recommended number of iterations for Argon2?

I've recompiled my operating system ("LionBSD" based on FreeBSD) to use Argon2i as the default password hashing algorithm in crypt/libcrypt. I'm wondering what the recommended number of iterations ...
-1
votes
0answers
18 views

C# to PHP partially decoded string [closed]

Hello I am trying to send data from c# application to my webserver. And I got like 99% of data decrypted right now the use of URI.encode helped me a lot to increase sucessfull decryption by many %. ...
3
votes
0answers
40 views

A few questions about CRC basics [migrated]

I am an electronic engineer and have not found it important to consider CRC from a purely mathematical perspective. However, I have the following questions: Why do we add n zeros to the message when ...
0
votes
0answers
15 views

How much bandwidth is used in a typical IKE/ISAKMP initialization?

How much bandwidth is used in a typical IKE/ISAKMP initialization? How many UDP packets are sent in each direction, and what is their typical size? I'm referring to initialization of IPsec via IKE/...
2
votes
1answer
39 views

what kind of custom header add to encrypted file to identify my encryption,consider safe and reliable.like pseudo format extension or file size

I want to add some custom header to encrypted file to identify my encryption,consider safe and reliable.like pseudo format extension or file size.Is there any algorithm or tool to make it?
4
votes
3answers
209 views

After a diffie hellman key exchange, what is the common secret used for?

What is the common secret that is established used for? What types of interactions are now possible?
2
votes
1answer
25 views

Older key as PGP subkey?

Currently I have a 2048-bit PGP key. Suppose I create a new 4096-bit key. Can I add that old key as a subkey of this new one?
3
votes
1answer
48 views

Is a hash function used to expand the key after ECC shared secret is complete?

I am trying not to solicit opinions, but I have not been able to find a reference to the question at hand. I have designed an ECC engine in silicon that handles any curve in the form of $y^2 = [ax^3 +...
0
votes
1answer
44 views

How was the AES MixColumns matrix constructed?

How was the constant matrix in AES MixColumns constructed? \begin{bmatrix} 02 & 03 & 01 & 01 \\ 01 & 02 & 03 & 01 \\ 01 & 01 & 02 & 03 \\ 03 & 01 & 01 &...
0
votes
0answers
23 views

Decryption of fields in MS Access DB [closed]

I want to interact within my c# app with another programs database. this is stored in Microsoft Access format. But thats not the point. There are some fields whose content is encrypted, and i don't ...
2
votes
0answers
22 views

LENGTH Parameter in the EEA2 AES-128 of LTE

In the EEA2 option for encryption in LTE the AES-128 algorithm is mechanized. There, the nonce used in the CTR Mode is a 128-bit value. The first 64-bits are covered by a COUNTER, a BEARER, a ...
-1
votes
0answers
48 views

Computational Cost : Scalar Multiplication vs exponentiation in elliptic curve

$Pub=\gamma P$ and $Pub=P^{\gamma}$ where $P \in G_{1}$ and $\gamma \in Z_{p}$ Which one has less computational cost?
0
votes
1answer
39 views

Hash Function representation in identity-based encryption

Some describe as $H:F_{q}\times G_{2}\rightarrow \{0,1\}^{n}$.Some describe as $H:\{0,1\}^{*}\times\{0,1\}^{*}\rightarrow F_{q}$. What is the meaning of product function? what kind of operation does ...
1
vote
0answers
62 views

Homomorphic encryption over finite fields

I'm curious on the following question: let $\mathbb{F}_{2^n}$ be a finite field which is an extension of $\mathbb{F}_2$ with order of $n$, is there an encoding scheme $e:=\mathbb{F}_{2^n}\rightarrow \...
3
votes
1answer
81 views

Why does 3DES need private key to decrypt?

I create two files, my.cer and my.pem ( include certificate and private key), I encrypt a file with my.cer, I use openssl smime -encrypt command. When decrypting data, it needs my.pem. I think 3DES ...
6
votes
0answers
71 views
+100

culling equivalent Enigma keys for short messages

The following for-loop iterates over all possible keys for an M3 Enigma for three selected rotors: ...
7
votes
3answers
171 views

Encryption-then-encode or encode-then-encryption?

I have this question in which I m struggling. I have read in many sites about encrypt-then-mac etc. If the confidentiality for transmission is needed, discuss the feature for the order of encryption ...
3
votes
1answer
59 views

What would currently make the strongest https connection?

when you look at the encryption websites use you will see that there is alot of diversity, some use 256 bit keys some do not, some use DHE-RSA some ECDHE some use sha 256 some sha1, but my question is,...
3
votes
1answer
56 views

Does encryption of data/information take place in peer to peer networks like Gnutella, Bittorrent?

Do peer to peer networks like Gnutella, Bittorrent have any encryption system to secure the users privacy or encrypt the file/data being shared? Elaborate please.
-3
votes
1answer
58 views

bruteforce on aes 256 cbc mode

i have a series of encrypted text , they encrypted by aes 256 bit cbc mode for every encrypted text there is an iv that i have them also and i know its algorithm is aes 256 bit cbc mode i can ...
2
votes
1answer
52 views

Is PKCS7 a signature format or a certificate format?

I always though PKCS7 was a signature format. However, on the net I find several references to PKCS7 being a certificate format - for example, this talks about PKCS7 certificate: Extract raw ...
3
votes
2answers
55 views

Output of a Linear Shift Register given Plaintext and intial state

Given an initial state $S_0 = (0101)$ and plaintext $P = 1010101011$ I need to find the ciphertext. The method to solve this was not taught in my coursework, and the information I have found online ...

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