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.
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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.
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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 ...
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PGP key pair - How to set up for multiple users to decrypt messages with Kleopatra [migrated]
This is my first project of this nature, and I am hoping this is a basic use case for PGP encryption. Please forgive my ignorance!
There is a server being configured by a service provider (SP). The SP ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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....
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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:
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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 ...
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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 ...
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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?
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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 ...
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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 ...
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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 ...
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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 ...
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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, ...
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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.
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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 ...
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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 ...
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Keyspace in Encryption using Chaotic Maps
I wish to encrypt an image using Logistic map. A Logistic map can be specified with the Equation:
$$x_{n+1} = r\,x_n (1-x_n).$$
Now, according to the Kerckhoff principle, the entire system's security ...
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Accidentally leaked my main gpg private key!
I only use one gpg key, which I use with pass, which currently holds a ton of password stuff. I also use that key to sign my github commits and a ton of other stuff....
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AES first and last round key whitening
I've found this question from 2014 on Key Whitening: How exactly does key whitening manage to increase security? where is said that AES applies key whitening internally by adding a sub-key prior to ...
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Can the encryption with CTR mode be replaced by a publicly known unkeyed permutation when doing multiple encryption and keeping the IV secret?
A user of this forum answered in one of my questions and said that if the IV is kept secret in multiple encryption with CTR mode, the cost of breaking the scheme is $${2^{2 l_{key}}} 2 \cdot {2^{l_{iv}...
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What qualifies as a key?
For my own project and the fun of it I have created an algorithm that turns plain text into cipher by interacting between entered text and a given password. My question is, in this instance, does the ...
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Is BLAKE2X suitable for generating keys with any security in bits event if BLAKE2 having only 256/512-bits?
I can generate a key of any security in bits with any hash function from random source with enough entropy by using the following scheme:
$$H(00||S) || H(01||S) || H(02||S) || H(03||S) || \cdots$$
/\ ...
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Encrypting with CBC then XORing repeatedly a chunk of random data smaller than the plaintext: Is there a gain in security?
If I encrypt a 1MiB file with AES-CBC (or any other cipher) and XOR a 128KiB of (truly) unpredictable random data repeating until the end of file, will I have a security of 1048576-bits (128KiB*8)?
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Is it possible to create a pseudo-One Time Pad by using a key smaller than the plaintext?
Let's suppose I want to encrypt a 10GiB file but I don't want to use a One Time Pad, just a 1MiB key taken from /dev/random (in Linux).
I know that the key should not be repeated, but is it possible ...
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Hashing a seed together with a block counter and using as a encipherment scheme: What scheme is more secure in practice?
This question is related to this (but it is not the same).
Let's suppose I have a seed with an entropy of 1024-bits and hash it with a counter using a hash function with one-quarter of the seed size ...
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Signature operation of RSASSA-PKCS1-v1_5 requires private key. Superficial limitation, or are public parameters mathematically incapable of it?
In the case of RSASSA-PKCS1-v1_5, is it simply that the cryptographic libraries and APIs are designed to only sign if determined superficially that it has a private key, or is the public key ...
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Blom's key distribution
Having a difficult time wrapping my head around the Blom's key distribution. I found an online resource to understand this but still couldn't get it.
I am attaching the screenshot from the book where ...
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How much computation it takes to crack a PBKDF2's secret salt when the passphrase meterial has been leaked
Given the following code, extracted from a Bip39 implementation for Android by Zcash
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Standardized names of cryptographic algorithms
I am using micro-services to interact between various cryptographic technologies like HSMs, keystores, vaults, etc., that are written in different languages. Usually, each technology, or even vendor, ...
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Hashing a seed together with a block counter and using as a encipherment scheme: Will this have the same security in bits as the seed used?
A user of this forum said that the whole entropy of a seed goes to the hashed result if using a counter and also that is suitable for key generation even if the internal state or digest size of the ...
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Encrypt messages for two-participants chat
I need a chat between two users and I obviously want to make it as secure as possible. I am, by no means, a cryptography expert, so I turn to you guys for some advice.
Because I like the idea of ...
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Is it possible to generate a key from a hash function, being the key larger than the hash function digest output without spliting the seed?
Let's suppose I have a 2MB photo and I want to generate a key from it, and the key should have 2048-bits of size.
A hash function such as SHA3-512 would not deliver a key with with the desired ...
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Streams Ciphers - Linear feedback shift register logic behind design
I’m just seeking a better understanding as to the logic behind design of the A5/1 cipher’s keystream generator. Why are the registers degree chosen in such a fashion (19,22 and 23 bits long ...
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Risk scenarios when hosting KEK in Google Cloud KMS HSM backended [closed]
For some time now, we have been assessing the risks from a GDPR perspective when data (data-at-rest) in the Google Cloud is fully encrypted using native means. This means that we create both the KEK ...
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Generate SHA256 fingerprint from RSA public key (string only)
I have the public key, the string itself (not a file), and I am trying to figure out the SHA256 fingerprint, as in the image attached. The default key generated by PuttyGen is SSH-2 RSA with a SHA256 ...
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Storing keys in HSM program flash
We are using an Infineon uC TC233 for a cybersecurity based development. It has HSM but no HSM Data Flash (DF1) present. Our host side application will call HSM APIs itself for any crypto service.
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Can initialization of the Spritz cipher state by a randomly chosen permutation securely act as a key?
The Spritz cipher is a "sponge-like" construction that the authors show can be used as a hash, MAC, stream cipher, re-seedable pseudo random number generator, and/or an authenticated cipher.
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How to destroy a randomly generated key after using it?
for example, I have an encryption program like this:
Input: a message, M; my public key Kpub
Step 1: randomly generate a ...
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In a Diffie-Hellman key exchange Find this key and compute the shared secret key k
Hi I struggling to find the answer of my schhol exam, can anyone help me .
In a Diffie-Hellman key exchange the multiplicative group of integers modulo
p is used with the parameters p = 59, g = 3 mod ...
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What is the importance of superencryption?
Please, can any extensively explain the importance of super encryption in relation to attacks experienced by single standard algorithms
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Cryptography methods that allow for multiple keys to be used?
I'm currently working on a webapp in which I'd like all nearly all user data to be encrypted, but accessible by multiple users (ie a doc encrypted should be decrypt-able by parties A, B, C, all ...
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Do PQ-KEMs kyber and KEMs approved for 4th round , need Domain Separation?
Do PQ-KEMs Kyber and KEMs approved for 4th round , need Domain Separation for deriving multiple keys from shared secret?
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Is libsodium's Key Exchange system secure?
I'm building a project using libsodium's AEAD + Key Exchange system and want to write a proof justifying the security of the project. I am wondering if I can find a source detailing the exact security ...
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