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Questions tagged [cryptography]

Cryptography is the collective term for algorithmic techniques used to secure data from unauthorized entities.

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Can I fix this encoding issue with a copy and pasted .p12 Certificate?

Wondering if there is a work around, whether it be from advanced settings in Gmail or another text editor or command line fix for a pretty stupid issue. I hastily opened a .p12 Certificate in Notepad, ...
Jeffrey Hlavac's user avatar
0 votes
1 answer
82 views

In OpenVPN, which is the difference between EC and ED? Is it needed DH file when I use elliptic curve?

In a OpenVpn connection, I would like to use an elliptic curve, but I don't know what is the difference between EC and ED. Which is better? Also, in some documents I read that exists ECDH, that if I ...
Álvaro García's user avatar
0 votes
0 answers
212 views

Recover Machine Key that was not marked as exportable upon creation

We have a machine key that is located in: C:\ProgramData\Microsoft\Crypto\RSA\MachineKeys that was probably generated using the command aspnet_regiis "MyKey" -pc. The key works fine although ...
Calum's user avatar
  • 101
1 vote
1 answer
1k views

What does the OpenVPN 'auth' directive do?

What does the 'auth' directive do in an OpenVPN config file? I am using a PKI system with my OpenVPN setup, as detailed here, and i have got everything working OK (I.E Client connects to server). ...
M_D's user avatar
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1 vote
0 answers
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GPG allows importing an invalid secp256k1 public key

I came across a PGP public key that seems invalid. The key is a secp256k1 public key that supported by GPG. In fact, GPG allows importing that key even if it has an invalid secp256k1 public key inside....
Andreas Tzionis's user avatar
1 vote
0 answers
4k views

Exporting non-exportable private key for .cer from Windows Certificate Manager

Problem Like many others, I am trying to export the private key associated with my .cer file to convert to .pfx. There are a number of hacked solutions e.g. https://stackoverflow.com/questions/...
Sterling Butters's user avatar
1 vote
0 answers
1k views

Timeout using cryptsetup passdev in crypttab

firsty I know it is not very safety storing the key on a stick but I am lazy and let's say I run around with a implanted usb-drive ;-) The scenario is the following. Disks: sda ...
muxLeet's user avatar
  • 11
1 vote
0 answers
487 views

Convert Tor keypair to hex or base64 format

I just generated a Tor key with mkp224o, and I ended up with this (example) output file: == ed25519v1-secret: type0 ==∏ — ¯£«• UJ’Î˙Ù¬ §π¯_˚ÑÆE Œ«ß˝†òyflsk¸¬ì–Ôâm ù≤Ü(~”ö}Ù I want to get a ...
Ben Zelnick's user avatar
6 votes
1 answer
1k views

How do I sign a file using SSH and verify it using a certificate authority?

I would like to give a selected number of developers ability to run code on a system, and verify it using OpenSSH's -Y verify feature. # Generate the certificates, and sign the dev cert with the root ...
Dvidunis's user avatar
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0 answers
271 views

Renew a self-signed certificate

Let's say I have a self-signed X.509 certificate: file some.bin some.bin: Certificate, Version=3, Serial=00ea5db390c4cc0de3, Issuer=Some Certificate, not-valid-before=2022-08-02 06:51:44 GMT, not-...
JohnnyFromBF's user avatar
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0 votes
1 answer
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Duplicity cron not working

I'm trying to run Duplicity backups via a cron script with --encrypt-key and a GNUPG key ID (from gpg --list-secret-keys). It's failing with /root/backup.sh: 5: --encrypt-key: not found but if I ...
Sam's user avatar
  • 180
2 votes
1 answer
545 views

Are RSA and ECC certificates interchangeable?

Can I use a ECC certificate if a service/software (according to documentation) requires an RSA certificate? Does the software need explicit ECC support?
k-eight-s's user avatar
1 vote
1 answer
102 views

How can I use zero-knowledge proof as a user to encrypt a text document?

I have a text document for which I don't want to reveal the whole contents, but I want to release some information about it in advance to claim the originality later. For example, if the text document ...
Jineon Baek's user avatar
0 votes
1 answer
1k views

How to convert this file into PNG

I have a file with no extension (as far as I can tell) that consists of special symbols. (File: https://drive.google.com/file/d/1h9MuUDfDtGEneEzZMNKLKWwY7JjZlBTS/view?usp=sharing) Here're a couple of ...
awayneff's user avatar
0 votes
1 answer
129 views

UEFI Encrypt disk on boot

I want to make UEFI/UFI encrypt disk with AES on boot, is it possible? If yes, how can it be done?
Andrew Duskin's user avatar
2 votes
1 answer
2k views

How can I convert my plain text (r,s) signature to a format that openssl can verify?

I have my (r,s) in the following format: ["r","442ca7cb054a9862ed93848cc13e0134968eba79db89e0e6f9ded510149aacd1","s","...
Felipe Tomao's user avatar
0 votes
1 answer
82 views

How is the certificate encrypted?

I want to get an Apple CA certificate from the link https://setup.icloud.com/setup/qualify/cert?ver=P1.10.1 but I get an unclear file. How is it encrypted? Or how can you open it? i tried to save it ...
11 11's user avatar
  • 3
3 votes
2 answers
857 views

How should eMMC RPMB shared keys be stored?

Storing data in the eMMC Replay Protected Memory Block (RPMB) requires use of a shared key. RPMB read/write operations utilize the shared key to generate a Hashed Message Authentication Code (HMAC). ...
rda585's user avatar
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-1 votes
1 answer
181 views

Cant we use md5 like hash algorithms to store big data?

i've read a paper about how hash algorithms word in general and i saw one strange thing. MD5 input length is unlimited and the output length are always the same so isn't that mean you can turn any ...
Sarkar's user avatar
  • 105
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0 answers
758 views

How to do a clean installation of Windows 10 while keeping BitLocker enabled?

I didn't want to have to disable the bitlocker to format the PC, because that would definitely make it possible to recover data that has not been rewritten, and I value the security and privacy of my ...
J3ft3's user avatar
  • 1
2 votes
1 answer
2k views

How to blacklist certain ciphers and key exchange algorithms in ssh and sshd

To get a list of all supported algorithms, I can run ssh -Q kex, which on my machine outputs diffie-hellman-group1-sha1 diffie-hellman-group14-sha1 diffie-hellman-group14-sha256 diffie-hellman-group16-...
David Stone's user avatar
1 vote
0 answers
85 views

How can one disable supported crypto groups in Firefox's TLS support

I know how to enable/disable a particular cryptosuite in Firefox, with the settings like security.ssl3.rsa_des_ede3_sha in about:config. But I can't find how to do that with supported field groups, ...
Lionel Elie Mamane's user avatar
1 vote
1 answer
150 views

How to use b2sum in keyed mode?

Considering using Blake2 (perhaps b2sum) in conjunction to openssl dgst -sha512 -hmac $key but I don’t see an option to enable keyed mode.
sunknudsen's user avatar
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0 answers
89 views

How to verify sender email address is really the one displayed?

.Hi experts, There are ways to fake the sender email address as I have read. Meaning that if you receive an email, then the"from" email address visible on the frontend in your email client can in ...
johnsmiththelird's user avatar
1 vote
1 answer
2k views

Generate entropy to create RSA keys

I was wondering on how I could make my server as most secure as possible. I use OpenSSH to connect to it, using RSA keys. However, something bothers me about that method: to generate the RSA keys, I ...
Mathématix's user avatar
1 vote
1 answer
156 views

Generating (pseudo) random numbers from a log file (eg. /var/log/maillog)

First: I really know that a true random number generator should have real random input, like something that is impossible to predict. Now, consider this: A busy mail-server can generate tens of ...
Jeff Merlin's user avatar
1 vote
0 answers
515 views

What is C# RSACryptoServiceProvider doing under the hood when Encrypting using RSA?

When I drill down into the .Net source code I cannot find the code that actually runs when rsa.Encrypt is called, maybe it's running code within a DLL because I cannot find where the method is ...
MrNoise's user avatar
  • 11
1 vote
0 answers
50 views

How can I run John Walker's ent program effectively on some data streams?

So the original ent program can be found here. The website doesn't give me a sufficient explanation, so I ask, how can I use this program effectively on Windows?
user avatar
2 votes
1 answer
1k views

Convert Openssl explicit ECC public key to named curve public key

While generating ECC keys using OpenSSL we can specify whether we want explicit public key info or named curve. Named Curve: openssl ecparam -name secp256r1 -genkey -noout -out my.key.pem Explicit ...
user2940110's user avatar
0 votes
0 answers
1k views

unknown tag 26 encountered bouncy castle exception

unknown tag 26 encountered at org.bouncycastle.asn1.ASN1InputStream.buildObject(Unknown Source) at org.bouncycastle.asn1.ASN1InputStream.readObject(Unknown Source) at org.bouncycastle.asn1....
Onkar Narkar's user avatar
0 votes
0 answers
237 views

How to generate different public keys for each user in a system using openssl in linux?

I want to generate private public key pairs for each user(multiple users) in the system. I have the below code to generate that RSA *rsa = RSA_new(); BIGNUM *bn = BN_new(); BN_set_word(...
srccode's user avatar
  • 101
1 vote
1 answer
753 views

Is there a device or executable on Windows that can provide cryptographically secure random bytes via CMD or Powershell?

Essentially, I'm looking for the Windows equivalent of /dev/urandom on Linux. I know I can use Windows CNG via the C++ APIs, but no idea if there's an available (portable) method to access random ...
Morgan's user avatar
  • 165
2 votes
1 answer
3k views

Load key “ec256.pem”: invalid format is thrown on trying to generate public key from private key

I am trying to generate public/private key pair using ECDSA curve secp256k1 On generating public key from ec256.pem (private key) the following error is thrown "Load key "ec256.pem": invalid format" ...
Hema Vajravelu's user avatar
0 votes
0 answers
36 views

Encoding a PDF using matrix multiplication

I need to encode a patent application in a PDF file using matrix multiplication on Mathematica so I can save it on a cloud storage service so my partner can download the encoded file in Asia and ...
Joe Coletta's user avatar
0 votes
1 answer
381 views

How can I show installed CSP's on my Linux system without using the cpconfig util?

How can I show a list of installed Crypto Service Providers without using cpconfig or csptest? How can I check if there's a CSP on the current Linux system? The system is not mine and I'm told to ...
Silvan's user avatar
  • 3
3 votes
0 answers
1k views

What is the "TLS_GREASE_BA" cypher in TLS?

I've just ran a client test on SSL Labs Client Tester and my client reports as the favourite cipher suite a cypher named TLS_GREASE_BA with a null key length. What is this cipher suite supposed to do?...
NeonMan's user avatar
  • 163
2 votes
3 answers
5k views

How to use MPIR with Visual Studio?

I am an academic and I need to develop some numerical algorithms which require functions from a package called MPIR http://mpir.org/downloads.html. I downloaded the 3.0.0 version and I am trying to ...
Turbo's user avatar
  • 139
0 votes
1 answer
60 views

HTTPS communication without requesting certificate

Is there a hack or the architecture of SSL/TLS allows communication with a Server without requesting it's certificate may be by pre downloading the certificate and installing it,The reason I'm asking ...
Kaleem Ullah's user avatar
0 votes
1 answer
2k views

CertUtil | How CertUtil -verifykeys works internally?

I have a CA certificate in Local Machine Certificate Store. When I run this command - enter code here certutil -verifyKeys gives Key "KEYNAME" verifies as the public key for Certificate "KEYNAME" ...
User1234's user avatar
  • 103
3 votes
1 answer
955 views

GPG/SSH: Making a key a subkey after the fact

I'm still new to GPG, SSH, and whatnot, and I'm not sure what best practice is. I have a USB device capable of generating and holding GPG||SSH keys without them leaving the device. It also permits ...
Prunus Persica's user avatar
-4 votes
1 answer
92 views

Can I use currency.js for commercial purposes? [closed]

I working on a cryptocurrency price tracker. I make use of the currency.js library. Can I use currency.js for commercial purposes?
Mehraj Khan's user avatar
-1 votes
1 answer
3k views

create private key from ECDSA public key

Public ECDSA Key Hex : 04d6597d465408e6e11264c116dd98b539740e802dc756d7eb88741696e20dfe7d3588695d2e7ad23cbf0aa056d42afada63036d66a1d9b97070dd6bc0c87ceb0d Public Address: ...
shahid's user avatar
  • 1
-1 votes
1 answer
584 views

Sapphire Nitro+ RX580 8GB Hynix Low hashrate?

I've got Sapphire Nitro+ RX580 8GB [Hynix memory] and it hashes on 21.9 mh/s out of the box without any overclocking or bios modding, as far as I know it should be higher around 24 mh/s, any ideas why?...
Broshi's user avatar
  • 99
2 votes
1 answer
503 views

gpg2 --edit-key addphoto / keytocard without password prompt

I am trying export subkeys to card for a keyring without any keyboard interaction using the command keytocard. This type of command is the same as addphoto as it requires to edit the keyring with --...
Bourinus's user avatar
2 votes
1 answer
1k views

gpg2 --quick-addkey without password prompt

I am trying generate in bash sub keys for a keyring without any keyboard interaction. I have tried several approach around what is mentioned here https://unix.stackexchange.com/questions/60213/gpg-...
Bourinus's user avatar
2 votes
1 answer
627 views

Windows 7 EFS, where are the FEK stored?

I feel confuse, I read from many technical doc from Microsoft and wiki. The FEK is generated for each file, and store in the file headers. But refer to this blog windows-7-how-to-use-cipher-exe-a-...
user avatar
1 vote
0 answers
3k views

How to get RSA Public Key and Private Key and get the modulus and exponent in plain text?

A requirement needs me to "Create or retrieve user’s RSA-OAEP key. There should be one public/private key pair for each user for a device" and send it to the server in this form: {"modulus":"...
Anton Unt's user avatar
  • 133
-2 votes
1 answer
56 views

Are forms of device encryption still bulletproof enough for the average user? [closed]

Even after drive and BIOS encryption, can the data on a device (i.e. a laptop) still be accessed by the thief? (if he/she doesn't have access to the token or password or linked key generator). ...
user19679's user avatar
  • 119
-1 votes
1 answer
4k views

Can You Copy the RAM contents as-is to File-System on Windows [duplicate]

My question: Is it possible to copy the contents of RAM to the file-system? (Windows) Additionally, is it possible to copy the RAM contents for a specific process? Reason: This largely revolves ...
Nicholas Summers's user avatar
0 votes
1 answer
235 views

How to Optimize a Dictionary / Word List?

I have a copy of a 4.09 GB wordlist / dictionary crackstation.txt. Just now the words and numbers are arranged in the usual order: 0123456789aAbBcCdDeEfFgGhHiIjJkKlLmMnNoOpPqQrRsStT uUvVwWxXyYzZ ...
OKCarl's user avatar
  • 1