Questions tagged [cryptography]

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

Filter by
Sorted by
Tagged with
0
votes
0answers
33 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 ...
0
votes
0answers
33 views

How does a “passwd” and “adduser” command actually work on a LINUX OS?

(From a novice's point of view) The other day I was thinking about how a typical "passwd" command works in a LINUX OS. For example, when we type in "passwd", a prompt appears letting us type in our ...
1
vote
1answer
167 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 ...
1
vote
1answer
51 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 ...
1
vote
0answers
123 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 ...
1
vote
0answers
38 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?
0
votes
0answers
119 views

Compiling NGINX from source with post quantum OpenSSL fork

I'm trying to compile/install an NGINX server in UBUNTU 16.04 with SSL enabled and I stumbled onto some problems. I want to configure the NGINX with a fork of openssl that has post quantum algorithms ...
2
votes
0answers
112 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 ...
0
votes
0answers
170 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....
0
votes
0answers
84 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(...
1
vote
1answer
142 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 ...
2
votes
1answer
1k 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" ...
0
votes
0answers
19 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 ...
0
votes
1answer
103 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 ...
1
vote
0answers
270 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?...
0
votes
3answers
2k 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 ...
0
votes
1answer
50 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 ...
0
votes
1answer
671 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" ...
3
votes
1answer
376 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 ...
-4
votes
1answer
87 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?
-1
votes
1answer
920 views

create private key from ECDSA public key

Public ECDSA Key Hex : 04d6597d465408e6e11264c116dd98b539740e802dc756d7eb88741696e20dfe7d3588695d2e7ad23cbf0aa056d42afada63036d66a1d9b97070dd6bc0c87ceb0d Public Address: ...
-1
votes
1answer
479 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?...
1
vote
1answer
259 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 --...
1
vote
1answer
841 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-...
2
votes
1answer
414 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-...
0
votes
0answers
2k 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":"...
-2
votes
1answer
50 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). ...
-1
votes
1answer
2k 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 ...
0
votes
1answer
149 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 ...
2
votes
1answer
400 views

Security: Is the Raspberry Pi really stateless?

The Raspberry Pi has become very popular. Because it is rather cheap and simple it could be an attractive device for people living in so called developing countries. However in many of these states ...
2
votes
1answer
42 views

Can an application that writes any data in a file be suspicious to an antivirus?

I am developing an application that, in order to work, needs to download data from the internet and store it in a .dat file. The problem is that some of that data is generated by other users. If a ...
3
votes
1answer
15k views

How to install openssl cryptographic library on Lubuntu

I'm trying to build cryptsetup 1.6.8 (or 1.7.0) from source using the openssl libraries instead of libgcrypt. ./configure --with-crypto_backend=openssl I did install libssl-dev but it still gives me ...
0
votes
1answer
114 views

Microsoft Certificate Store

I know that Microsoft Certificate store contains certificates with their corresponding private key. Now when using Microsoft certificate store, do we have to create it ? If yes then how ? or we get it ...
0
votes
1answer
255 views

How am I to install the 32-bit version of Google's NaCl SDK?

I'm looking at playing with Google's Native Client SDK, so I've downloaded the tool to install it, installed pepper_46, and attempted to build the "getting started" project, and I was given the ...
1
vote
0answers
510 views

How to transcode AES encrypted files with AWS Elastic Transcoder

I want to upload my encrypted videos to S3 and use Elastic Transcoder to transcode them. This is what I'm currently doing and isn't working at all. I'm using openssl to encrypt my video files. The ...
-1
votes
1answer
1k views

Corruption of a TrueCrypt file

Dear superuser people, this is my first question on the site so if I'm doing something wrong I apologize in advance :-) I've been using TrueCrypt for a few years now, not knowing they stopped ...
0
votes
0answers
1k views

AES encryption with plain text key using bash openssl

I am trying to encrypt a string using AES CBC. The output of the online tool (http://aes.online-domain-tools.com/) and the bash openssl command do not match. Can anyone help me with what I am doing ...
2
votes
1answer
2k views

Enable SCHANNEL Protocols in Windows Registry (Win7 & 2012R2) DisabledByDefault or Enabled?

I have enabled TLS 1.0/1.1/1.2 protocols on my local Win7 machine and 2012R2 server as well as disabled SSL 2.0/3.0 using the registry DWord value DisabledByDefault = 0 based on the following ...
0
votes
1answer
82 views

Encrypting multiple drives on a multi-boot system

So I am building a new system and I want to fully encrypt it, problem is I am not really sure how since I never encrypted anything bigger than a folder or zip. The build includes a Samsung 850 EVO-...
1
vote
1answer
1k views

What's the difference between certificate and credentials?

What's the difference between digital certificate (e.g. .pem or .der files) and credentials (e.g. .pfx files)?
1
vote
3answers
68 views

How can I cryptographically verify that someone owns the website they claim to?

More specifically, can I get them to sign a string of text with their x509 private certificate and then I can verify it using the public cert used by the website in question? Perhaps I could supply ...
12
votes
1answer
4k views

get x and y components of ec public key using openssl

I am generating a KeyPair for ECC from curve 'secp128r1' using openssl Steps I followed : first I generated a private key using the command openssl ecparam -genkey -name secp128r1 -noout -out ...
2
votes
0answers
92 views

3DES_CMAC encryption using online tools or OpenSSL

I have a smart card that claims that its mutual authentication is based on 3DES_CMAC algorithm. In the first step, the user sends a random number to the card and the card calculate the encrypted ...
6
votes
2answers
3k views

Beaglebone Black OpenSSl crypto acceleration

I'm running Debian Wheezy at my Beaglebone Black. Is OpenSSL using the hardware crypto accelerator by default? If no, how can I enable it?
-2
votes
1answer
70 views

Cipher challenge [closed]

So I was recently challenged by someone to solve this cipher. I am not entirely sure which section of the stack exchange this belongs but I think that this is ok for superuser. Below is the cipher (...
0
votes
1answer
44 views

Looking for new way to create password [closed]

I tend to use same 2-3 passwords for all sites and want to change that but want to make sure I standardize my new approach as well. Looking at password hashing and I know very little other than what ...
18
votes
2answers
8k views

GnuPG / OpenGPG: Recovering public key from private key

I know that the public SSH key can be recovered from the private using ssh-keygen -y. How can a (deleted) public key be recovered from the private key in GPG (preferably in a way that is OpenGPG ...
1
vote
1answer
741 views

Can I use a “Microsoft Office” Digital ID / certificate to sign PDFs in Adobe Acrobat?

I've been needing to sign PDFs lately - fortunately everyone's been fine with me using a self-signed certificate, however I feel it's unprofessional. I'm looking for a personal certificate I can use ...
3
votes
2answers
2k views

gpg2 - no option to select aes block cipher and outdated use agent?

With OpenSSL, I can select a what type of block cipher to use for encrypting a file. For example, if I want to encrypt a file with AES256 CBC block cipher mode: openssl aes-256-cbc -a -salt -pass ...
2
votes
0answers
205 views

Viewing and listing keys in MSCAPI CSP containers

I have a MSCAPI container created and hosted within a Windows Server 2003 environment. How do I use the command line to list keys and their details within the container onto the command line ?