Questions tagged [keys]

Private and secret keys consists of secret information used as input to various kinds of cryptographic algorithms such as encryption, signature and MAC to select the concrete transformation done by the algorithm.

Filter by
Sorted by
Tagged with
1 vote
1 answer
45 views

Is KangarooTwelve hash function suitable for generating very large key material as Shake-256 is?

If I take a large truly random portion of data, I know that I can generate a 2048-bits key with it (assuming the random data has more entropy than the key). I read in this forum that Shake-256 has ...
alpominth's user avatar
  • 391
0 votes
0 answers
83 views

Decrypt RSA knowing N, invp, and invq

im having a problem while solving a RSA problem, so i have python script to create a RSA key and cipher, from that i have n, invp, and invq. so my question is possible to decrypt the message only with ...
LM.'s user avatar
  • 1
1 vote
1 answer
175 views

Key exchange for encrypted firmware update

I'm trying to implement encrypted firmware update functionality for an embedded device. The goal is to prevent reverse engineering of our firmware when the update files are shared with our customers. ...
MDude's user avatar
  • 23
1 vote
1 answer
126 views

Double- and -add algorithm

I am currently doing the elliptic curves and I'm stuck for 8 hours without finding solutions. I under stand the process of double and add but don't know how to obtain 5 * 8P = 4OP =11 P. 11 P was in ...
Stefan's user avatar
  • 11
0 votes
0 answers
33 views

Enigma - Bombe - Understanding the relative values of ring settings to key settings

For a project, I am writing Enigma and Bombe simulators in Python. I have coded up both and so far so good. My Enigma simulator gives the same results as the online simulator here: https://people....
Andy Robinson's user avatar
0 votes
1 answer
155 views

Why does symmetric encryption not provide authentication and integrity? Is it only this type of encryption or cryptology in general have this issue?

Studying for Cryptology and came across a presentation regarding on "Integrity vs Authenticity" where the discussion briefly mentions how Encryption "does not provide integrity or ...
omar7439's user avatar
3 votes
1 answer
98 views

Key blinding security in Ascon

This article explains the role of key blinding in Ascon. Key blinding in Ascon involves XORing the key with the capacity part after the permutation in both the initialization and finalization stages. ...
hardyrama's user avatar
  • 2,074
0 votes
1 answer
192 views

How to calculate key length in bits?

On a technical forum discussion, an example key of 16 hexadecimal numbers was said to be 2048 bits in length. I do not understand this as each number would be 4 bytes - 32 bits - therefore to me 16 ...
Zonnkq Shad's user avatar
1 vote
1 answer
218 views

How to determine the prefix of a SECP256K1 compressed public key

I need to store a public key in a variable of maximum 32 bytes. I recover the compressed key and remove its prefix, but then I have to do the opposite: I have to rebuild the compressed address from it ...
Sino's user avatar
  • 11
0 votes
0 answers
33 views

Security Analysis: Adversary's Ability to Recover Concatenated and Hashed Secret with Partial String Knowledge

Suppose I have the following secret, calculated by concatenating and hashing the results of two random strings: secret = H( H( random_string1 ) || H( random_string2 ) ) Let's assume that the adversary ...
Kadir Korkmaz's user avatar
1 vote
1 answer
103 views

Manual entropy collection from sources with an arbitrary base

I'm writing a tool for manually collecting entropy from sources like coins and dice, and I'm wondering how to best deal with the case where the desired number of bits of entropy is not representable ...
Isaac's user avatar
  • 13
1 vote
1 answer
83 views

How does the key generation of a homomorphic secret-sharing protocol works?

I am new to cryptography and do not have sufficient background knowledge, and I am sorry for any possible vagueness in my question. I am reading a paper (https://eprint.iacr.org/2019/129.pdf) about ...
zhengyuansu's user avatar
0 votes
1 answer
70 views

Safe implicit value validation: $H_k(k \oplus m) \sim H_k(m)$?

$H_k$ is a cryptographic hash function that's keyed using a section of key material $k$ (for whatever definition of "keyed" that's appropriate for the given hash function $H$). Are the ...
aiootp's user avatar
  • 785
2 votes
1 answer
432 views

CTF - DES Challenge

I am trying to solve a CTF challenge based on DES. I attached the code of the challenge to the question. So far I have noticed that the otp used for the encryption is the same for the entire session, ...
Shark44's user avatar
  • 145
1 vote
2 answers
731 views

Are the null bytes produced by a True Random Number Generator a security issue when using it as a source of entropy for keys in One-time pad?

I can see that True Random Number Generators can produce some null bytes, after some megabytes of data, even 2 consecutive null bytes are produced: ...
alpominth's user avatar
  • 391
0 votes
1 answer
57 views

May I use the same One-time pad key two times if I encrypt it with a block cipher using two different block cipher keys?

Let's suppose I have two 2GiB files and I want to encrypt them using One-time pad (Vernam cipher), but I don't want to store two big keys. May I use only one key for the two files if I encrypt the One-...
alpominth's user avatar
  • 391
0 votes
1 answer
49 views

Derrive a new key from Trusted Third Party (e.g. Kerberos) session key

Kerberos (and I assume other Trusted Third Party protocols) use (hash) an existing shared secret key to create a session key used for authentication. I read that this authentication secret key can ...
Elliot's user avatar
  • 3
1 vote
1 answer
42 views

Security of keys that are as long as the data

If both communicating sides end up with the same secret 3000-bit key, is it enough to XOR each byte of the messages with each byte of the secret key to make it secure? Wikipedia says it is, but I ...
Kevin Stefanov's user avatar
1 vote
2 answers
112 views

What is simple asymmetric encryption that use arbitrary key?

While XOR is used as simple symmetric encryption with arbitrary custom key, what is a simple asymmetric encryption that use arbitrary custom key? That means I want to be able to set custom private key ...
Muhammad Ikhwan Perwira's user avatar
4 votes
3 answers
919 views

If I encrypt a plaintext with different keys for each block, will I have the same security as a one-time pad?

Let's suppose I encrypt an 1MiB plaintext with AES-256 in ECB mode but using different keys for each 16-byte block (I know this is weird but it's just an example). Remembering that a different 256-bit ...
alpominth's user avatar
  • 391
0 votes
0 answers
29 views

Genrerate n numbers based on a string [duplicate]

I wanna generate a list of numbers based on a unique string. They shouldn't be predicatble and every time to generate they are the same. Could someone help me pleeease :)?
Jonathan Krützel's user avatar
0 votes
1 answer
68 views

If encrypting with a hash function in counter mode, will the security of this scheme be at most minimal{input,output}?

It's possible to use a hash function as an encipherment scheme if used in counter mode. Let's suppose I take a 64-bytes (512-bits) seed/key and hash it concatenated with counters, and use it as a ...
alpominth's user avatar
  • 391
0 votes
0 answers
109 views

How do I decrypt a key encrypted by my HSM under a ZMK?

I've generated a key using an HSM Thales PayShield and i have share it with a counterpart. I followed these steps: i generated key usign KG console command i use FK to form ZMK from clear components ...
MaXbeMan's user avatar
0 votes
1 answer
159 views

How to find the round key in AES 256

Can anyone explaine how to find the every 15 round key by the 64 hex digit master key of AES 256 please. I will be really greatfull
james's user avatar
  • 1
0 votes
0 answers
36 views

DES encryption Key from a passphrase

I have been given a DES encryption assignment. I was given the Cipher text, the Plain text and the "passphrase". The passphrase consist of a 4 byte hex string. I have studied several ...
RikiD's user avatar
  • 1
0 votes
1 answer
48 views

Are asymmetric encryption and decryption same function? [closed]

In asymmetric key encryption, we have 2 functions, encrypt(m,k) and decrypt(m,k), and 2 keys, ...
Juan's user avatar
  • 9
0 votes
0 answers
99 views

PCI compliance - use of ANSI X9.17 for export keys

we have a concern about a key export. We completed the migration to Key Block LMK in our environment (with HSM Thales 10K). Now, we have to exchange keys with third-parties that still use Keys in ...
MaXbeMan's user avatar
0 votes
1 answer
118 views

Clarification on the use of Key block Version ID with Thales HSM

Clarification on the use of Key block Version ID For the first time since we migrated to the Key Block we are exchanging keys with third parties, The keys were all generated by choosing Key Scheme &...
MaXbeMan's user avatar
7 votes
2 answers
196 views

Providing tokens for anonymous survey

I want to conduct an anonymous Internet survey (e.g. “What’s your favorite fruit?” with a multiple choice answer) among a given set of people. Double answers by the same participant are not allowed. ...
Alfe's user avatar
  • 209
1 vote
0 answers
76 views

Issue with AWS Encryption SDK for JavaScript in Browser: 'Buffer is not defined' [closed]

I'm trying to implement AWS Encryption SDK for JavaScript in a browser environment within a React application. When I attempt to construct an instance of the encryption client using buildClient ...
CreativeDesign's user avatar
2 votes
1 answer
81 views

Security of RLWE encryptions of secret keys

Under which conditions is it secure to publish an encryption of the secret key $s$ under itself in terms of an $RLWE_s(s)$ ciphertext? Because for some schemes this is (repeatedly) used in ...
opag's user avatar
  • 43
2 votes
1 answer
87 views

Key management problem in federated learning based on homomorphic encryption

In federated learning using homomorphic encryption, all participants in most schemes share the same pair of keys, which can easily cause key leaks and lead to data privacy leaks. After research, I ...
sunmu's user avatar
  • 41
3 votes
1 answer
116 views

What is the result of not connecting the 1st register to the xor gate in LFSR?

I designed 8 bit lfsr in vhdl. According to mathematical theory, I xor processed the outputs of registers 1, 4, 5, 6 and 8 and connected them to the input of register 1. theory says that if I give the ...
Doğukan Karakaya's user avatar
2 votes
2 answers
65 views

DES initial key generation

I am working through a textbook on crypto, currently on DES section. What bothers me is that there was no explanation about where do we get initial 64-bit key from. This question is also very hard to ...
Michael Hammer's user avatar
0 votes
1 answer
132 views

If I encrypt two plaintexts with different keys, XOR the ciphertexts and send to an adversary, what can he/she do with what I sent?

Let's suppose I encrypt two blocks of 1MiB with AES-256 in CBC mode, each one using different keys, XOR the resulting ciphertexts and send this XORed block to an adversary. Remembering that the ...
alpominth's user avatar
  • 391
0 votes
0 answers
60 views

Hashing a seed full of entropy with a cryptographic hash function and emiting a key with the same size as input: can a collision attack occurs?

I read this in the documentation of HighwayHash: By contrast, 'strong' hashes such as SipHash or HighwayHash require infeasible attacker effort to find a hash collision (an expected 2^32 guesses of m ...
alpominth's user avatar
  • 391
1 vote
1 answer
43 views

Is it safe or reasonable to use the key parameter in a cryptographic hash function as a counter?

Not all the cryptographic hash functions have the counter parameter for making messages be different for each counter value. But many accept a key parameter. Is reasonable to use the key parameter as ...
alpominth's user avatar
  • 391
0 votes
1 answer
122 views

How does the public key cryptography algorithm generate a public key based on the private key? [closed]

Because of the need of the project, I want to develop a simple public key cryptography algorithm, but I have doubts when generating the key pair. I have learned about the key generation process of RSA....
SN-Grotesque's user avatar
1 vote
2 answers
76 views

How is asymmetric encryption possible if you need a passcode in order to encrypt something?

Cant you look at the algorithm used to encrypt and find the private key from the public key that way? As an example, here's a simple python algorithm that encrypts an input: ...
Javier Albarracin's user avatar
1 vote
0 answers
50 views

Can new decryption keys be issued without modifying the encrypted contents? [closed]

I'm curious if there's an encryption scheme where content may be encrypted to a public key where the associated private key can generate new decryption keys for the same content. The goal is to ...
Kai's user avatar
  • 11
1 vote
1 answer
129 views

Why hashing a seed to generate a key and using chaining to get the rest of key matterial is not secure?

Here, an user says about using a seed to generate a key that is larger than the digest size: "Do not use hash chaining: that's a bad way of constructing a key derivation function from a hash. If ...
alpominth's user avatar
  • 391
0 votes
1 answer
453 views

SPKI Public Key to Compressed Public Key

I currently have a DER-encoded X.509 ECC SECP256K1 public key, also known as SubjectPublicKeyInfo (SPKI) from AWS KMS. How do I convert it to a 66 hexadecimal compressed public key string?
yijie's user avatar
  • 3
1 vote
0 answers
61 views

Need clarifications AWS Cloud HSM architecture [closed]

My apologies for the long post. I read on AWS docs that, when keys are generated using java keytool, the certificates are stored ...
arjunballa's user avatar
1 vote
1 answer
37 views

Symmetry shares

I’m sorry if this is already answered, however, regarding symmetric key components to create a symmetric key using xor (So eg comp1 xor comp2 xor comp3 = key) If in the case of an AES KEY, which goes ...
talisman's user avatar
3 votes
0 answers
114 views

AES subkey calculation not working for subkeys beyond 0 and 1

How should I generate the remaining keys when performing subkey generation in AES encryption? I generated keys 0 and 1 first, but the other keys I generated later were wrongly generated, so what steps ...
Mohamed Mohamed Mourad Abdel W's user avatar
6 votes
2 answers
1k views

Always set the IV to 0 randomized CBC

Please explain what goes wrong if we always set the IV to 0 in randomized CBC, and use the system to encrypt two different messages m0 /= m1 with the same key k. I ...
Amirhossein's user avatar
9 votes
2 answers
3k views

How strong are Bitlocker recovery keys?

This is an example of a bitlocker recovery key; 820042-335825-646573-481530-265253-688132-339900-822810 İs that key actually strong? It does not have any letters, ...
asd's user avatar
  • 91
1 vote
1 answer
56 views

X509 Client certificate - before - XEnroll / Certenroll / KEYGEN

IBM (now HCL) Domino has since way back a complete procedure to issue X509 client certificate as a login option to a webserver. Back in 2010-ish it worked fine in both Firefox and Internet Explorer. ...
Stefan K's user avatar
0 votes
0 answers
51 views

Client Side Encryption For Web Apps

I want to build something where web clients encrypt some data server side and store it with me. However, I am not sure how to manage the user keys - ideally they can just sign in with social to access ...
CSAMS's user avatar
  • 1
0 votes
1 answer
193 views

RSA Key Exchange Attack [closed]

I am curious what is an attack that the RSA Key Exchange algorithm is vulnerable to that Diffie Hellman Key Exchange is not vulnerable to? I know Diffie Hellman is prone to Man in the Middle attacks ...
CryptoGuru's user avatar

1
2 3 4 5
18