Key generation is the process of generating keys for cryptography. A key is used to encrypt and decrypt whatever data is being encrypted/decrypted.

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Are there any security implications in creating an SSH key for the root user?

I've written an install script on a server to quickly set up new sites in the /srv directory. It needs to do a git clone, and has to be run via sudo in order to have the permissions to do all the ...
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1answer
37 views

Are WoSign S/MIME certificates generated on the server side and therefore unsafe to use?

WoSign has been in the media for offering free server and client certificates. Since one of my (free) S/MIME certificate from another CA is about to expire soon after one year and WoSign offers ...
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32 views

InvalidKeyException using ECPublicKey [migrated]

I'm getting the following exception when i try to encrypt a byte array with a EC public key : java.security.InvalidKeyException: No installed provider supports this key: ...
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1answer
40 views

Does AES 256 encryption support a master key and generated (time-bombed) keys?

I have a scenario where semi-sensitive [1] data for a corporate web application is to be stored in the browser's localized storage (Indexed DB to be specific, via JavaScript). The intention is to ...
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1answer
32 views

Determine private key size using public certificate [duplicate]

I have a public certificate in a PEM (.pem) file -----BEGIN CERTIFICATE----- MIICsjCCAZqgAwIBAgIJAMA1YIQ2JLXDMA0GCSqGSIb3DQEBBQUAMBExDzANBgNV ... 29V/R9RZOoSBHDzGPL84wm4qojMuwQ== ...
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1answer
150 views

Can i know how chosen ciphertext attack work on textbook RSA

I am very new to cryptography and I am confused with something? Here is the homework question I am having trouble with: Write a program to attack the Textbook RSA Encryption Scheme, in order to ...
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775 views

MPPE-Send and Receive key derivation from MS-CHAPv2

I am trying to get the MS-MPPE-Send-key and MS-MPPE-Recv-key from the MS-CHAPv2 challenge material. I am able to follow the RFCs 2548 3078 and 3079 to the step of getting the GetNewKeyFromSHA() it is ...
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Can I use the output from a DRBG directly as K for AES, or do I need to use a key generator algorithm? [migrated]

NIST has 3 validated "Recommendation for Random Number Generation Using Deterministic Random Bit Generators" (DRBG's) that are based on NIST SP 800-90A: Hash_DRBG (based on hash functions) ...
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1answer
56 views

JSON Web Tokens - How to securely store the key?

I was building a RESTful Web Service when I came across JSON Web Tokens as an alternative to traditional cookies for authentication. The concept core of this method is that the server is the only ...
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1answer
56 views

PKI/Why does Microsoft require my cert before encrypting an email?

Microsoft doesn't allow sending public-key encrypted messages using Outlook 2003-2012 on Windows 7-8x environments without first creating your own Digital ID or private key for signing. Per ...
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3answers
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Is it safe to generate a password for a user during sign up in a web application?

I'm working on updating a web application. It currently creates a password for a user during sign up. Is asking the user to create the password themselves safer than relying on a generated password?
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21 views

OBKG on smartcard with PKCS#11

I have a new smart card with an on board PKCS#11 module and operate in a Win 8 environment. Like many cards, it can generate its own key pairs for enhanced security (only the public key can leave ...
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1answer
8k views

Create RSA public, private key pair having numbers generated already

I want to know to to generate working RSA key pair, with correct syntax. Let's say i have already generated somehow my numbers for 512bit key, which are: e = 00065537 d = ...
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2answers
125 views

How to properly transition from standard PGP keys to using subkeys?

When I initially set up PGP, PGPTools didn't prompt me to create separate subkeys, as explained in the article "Creating the Perfect PGP Keypair". Now that I've learned a bit more about PGP, I'd like ...
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2answers
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What is the difference between DHE and ECDH?

I learned that perfect forward secrecy is implemented through DHE and ECDH but what is the difference between these 2 key exchanges? Also can someone explain how perfect forward secrecy works? I've ...
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1answer
27 views

Session key renewal between two constrained devices

I'm not keen on encryption and security overall, so please forgive my ignorance. Let's assume the following: We have two nodes which are constrained devices (resources not sufficient for asymmetric ...
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1answer
126 views

Generating secret keys with secret keys

Hydra is a secretive organization. It is comprised of several Directors at the top, and many Agents underneath them. A Director sends Agents on secret missions. During these missions, communication ...
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7answers
613 views

Is it possible to make a more secure random number generator algorithm by XORing two or more less secure random number algorithms?

Is it possible to make a more secure random number generator (e.g. for cryptologic purposes) by combining two or more less secure random number generator algorithms using XOR? Here is an example of ...
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1answer
82 views

Safely encrypting data received through HTTPS

I am receiving sensitive data over an HTTPS connection and need to store this on disk, encrypted so no one can tamper with it, but for reading later on. Each user in the system has a password. The ...
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1answer
119 views

RSA key generation: gpg vs openssh

When I generate RSA key for ssh (both server-side and client-side): dpkg-reconfigure openssh-server ssh-keygen the key generation is completed instantly. However, when I generate RSA key for gpg, ...
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1answer
44 views

PCI compliant RSA key generation and getting value of private exponent

Is it possible to generate RSA key and get its private exponent in clear and to be compliant with the following PCI requirement?: Keys must be generated so that it is not feasible to determine that ...
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21 views

Safenet iKey 4000 RSA key pair generation in FIPS 140-2 compliant mode

I need to generate RSA key pair and show the public and private key on screen (in a secured room). The algorithm must be FIPS approved. So I would like to use iKey 4000 which is FIPS 140-2 level 3 ...
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How should API keys be generated?

I want to make sure requests can't be forged and sent on to my server. In order to do this I need to generate an API key per user on my system. The purpose of the key will be to sign requests on the ...
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Why is the entropy of a session key approximately half the number of bits in the key? [duplicate]

From this OWASP page on "Insufficient Session-ID Length", it states: Assuming that the session identifiers are being generated using a good source of random numbers, we will estimate the number ...
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How is Tresorit client-side encryption key stored and managed?

I am using Tresorit on Mac OS X and iPhone. When I am using it there is always applied client-side encryption before posting the file to cloud. The key used for encryption is AES-256 and CFB mode of ...
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Distribution of key by server

I have read that in asymmetric cryptography, a system admin can generate key pairs on the server. After that, the users will be given the generated key pairs and this is an efficient way of doing this ...
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63 views

Same RSA key pair for all users

Let's say in my computer running Debian i have an RSA key pair generated by user foo and copied the public key to server_A for allowing key based authentication in ssh for foo. Now my question is can ...
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Calculate time taken to break AES key

A 256 bit AES key is required to be broken using the brute force method on a 2GHz computer. How long would it take to break the key in the best case and in the worst case situations? Assume that 1000 ...
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Should you notify software vendors that their software has been cracked?

Apologies if this is not the right place to ask this question, I will happily move it to another Stack Exchange site if need be. Before I explain the rationale behind the question, let me clear up a ...
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24 views

What is the difference between “TLS” and “NETLOGON Secure Channel” authentication?

I would like to make sure what is the difference between "TLS" and "NETLOGON Secure Channel"(using signing and encryption) authentication? I know that TLS is aka SSL and I know that NETLOGON secure ...
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1answer
979 views

What is the point to the IPEK in DUKPT?

I'm trying to understand the DUKPT (Derived Unique Key Per Transaction) system used for PIN devices, but I'm getting hung up on the IPEK. This blog post has an image where the sequence is: BDK ...
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70 views

Looking for a way to encrypt/decrypt data using a generated key that works in Windows and Linux

I am looking for a way to encrypt/decrypt data on windows and linux platforms. The data gets encrypted in windows and the same data needs to be decrypted on linux/windows and vice versa. I understand ...
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Online Activation Succeeds, Website Registration of same Serial Key Does Not [closed]

I need to ascertain the validity of software I purchased. It passes one check (online activation) and fails another (registration of a software title at the manufacturer website). I am a belated ...
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Using HMAC to generate secret keys

I am developing a platform that uses several secret keys for several usages: key1 for hashing passwords (using pbkdf2-hmac-sha256), key2 to generate non-repeating unpredictable uuids (using aes-128 ...
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Question regarding RFC7296 (IKEv2) PRF+

In RFC 7296, in section 2.13 What do the "K", "S", and T# represent? And my follow-up question is, in section 2.14 What would be the K, S, and T# equivalent in {SK_d | SK_ai | SK_ar | SK_ei | ...
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1answer
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Key generation: Differences between GnuPG classic, stable, modern?

I plan to create a 4096 bit RSA&RSA key pair: gpg --gen-key --personal-digest-preferences SHA512 --cert-digest-algo SHA512 Is there any difference in generated key quality between versions 1.4 ...
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SSH key-type, rsa, dsa, ecdsa, are there easy answers for which to choose when?

As someone who knows little about cryptography, I wonder about the choice I make when creating ssh-keys. ssh-keygen -t type, where type is either of dsa,rsa and ecdsa. Googling can give some ...
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4answers
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Generate cryptographically strong pseudorandom numbers in Javascript?

Is there any good way to generate cryptographically strong pseudorandom (or true random) numbers in Javascript? The crucial requirement: if a.com's Javascript generates some random numbers, no one ...
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4answers
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Why OpenSSL can't use /dev/random directly?

I couldn't find the answer for the reason anywhere, even the wiki page doesn't explain it. This seems like using a PRNG for seeding an another PRNG. The first one (/dev/random) may itself be seeded by ...
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How should I organize my keys?

Suppose I have a set of computers with variegate level of trust (for example): I fully trust my own desktop pc at home I trust a bit also my smartphone, but I know it could be stolen I trust a bit ...
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1answer
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Long passwords and key derivation functions

Not being a security expert, I have a rather theoratical question that I have been thinking about for quite a while now: Let's imagine an encryption software that takes a user-provided password, ...
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1answer
120 views

How can I generate some public and private keys on both sides with low overhead?

We have an Authority Center (CA) generating some public and private keys for each client (more than one pair for each client). One method for sending keys to client is sharing a secret key between CA ...
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Public keys Quality

Is there any way to test the quality of generated keys from a public key cryptosystem? I've read about the common RSA attacks, but attacking the algorithm may not mean checking if the generated keys ...
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1k views

Running openssl s_client with an aes encrypted key fails

I'm trying to verify a 2-way SSL connection using the openssl s_client command openssl s_client -connect localhost:8883 -CAfile ca.pem -cert client.crt -key client.key The openssl s_client fails ...
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2answers
10k views

Creating user specific authentication methods in SSH

I have configured sshd on an Ubuntu server to use key authentication and it is working fine. I had to disable password authentication for key authentication to work. Server is always accessed via ...
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5answers
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What does key signing mean?

What exactly does the "key signing" mean? So for example I have a private/public GPG key so that people could send me encrypted e-mail, because they know my public key. But: what does key signing ...
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4k views

Is your PGP passphrase used to decrypt an encrypted private key, or needed in conjunction with the private key to decrypt the message?

If the former, then if the private key can be used to digitally sign messages, why doesn't your client offer to encrypt this highly sensitive piece of data? If the latter, then if someone had access ...
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1answer
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Why is using [x] to generate random keypairs a bad idea?

Anyone who has generated large GPG public/private keypairs has come across this annoying message: "Not enough random bytes available. Please do some other work to give the OS a chance to collect more ...
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1answer
276 views

What are the typical ways to generate a One Time Password?

I'm looking for the typical ways to generate a One Time Password. I know about the HOTP and TOPT. But, in my case, the problem is that the "server" only has a display as interface and the ...
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4k views

Generate a PGP key with more than 4096 bits?

I would like to know if generating a PGP key with a number of bits higher than 4096 is possible and if so how?