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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How do certification authorities store their private root keys?

Knowledge of a CA private key would allow MitM attackers to transparently supplant any certificates signed by that private key. It would also allow cyber criminals to start forging their own trusted ...
9
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1answer
994 views

Would it make sense to use Bcrypt and PBKDF2 together?

I've read various opinions about whether Bcrypt or PDBKF2 is a better key derivation hashing method. The answer seems to depend on a lot of complicated factors that are not easy to analyze. Would ...
8
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2answers
562 views

Can the human brain generate cryptographically secure random numbers?

A security conscious friend of mine was attempting to generate entropy using random dice rolls to generate a random password, and I became curious about the security of random number generators and ...
3
votes
3answers
856 views

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 ...
13
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3answers
598 views

Can I use the same password both for SRP and for client-side encryption?

Suppose a less-than-trusted server is used to store users' confidential data (encrypted at the client side), and both tasks - authentication and encryption/decryption - should be doable with a single ...
50
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4answers
19k views

What is the best practice: separate ssh-key per host and user VS one ssh-key for all hosts?

Is it better to create a separate ssh-key for each host and user or just using the id_rsa key for all host to authenticate? Could one id_rsa be a malpractice for the privacy/anonymity policies? ...
18
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4answers
7k views

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 ...
11
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5answers
6k 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?
9
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5answers
8k views

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 ...
5
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2answers
817 views

Best practice for password-protecting a secret key

What approaches are generally accepted for generating a password-protected symmetric key? My intuition is to generate and store a random string of appropriate length as the password-protected key, ...
26
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1answer
20k views

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 ...
19
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1answer
7k views

Where do I get prime numbers for Diffie-Hellman? Can I use them twice?

I realise it's very hard to generate suitable prime numbers and generators for the Diffie-Hellman key exchange. What is the best way to generate them? And if I have one, can I use it twice? ...
15
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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 ...
12
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3answers
13k views

What is the DUKPT Key Derivation Function?

I'm tasked with decrypting ciphertext acquired from an encrypted card reader. The card reader utilizes DUKPT(derived unique key per transaction) scheme and 3DES encryption. I don't have a problem with ...
7
votes
3answers
5k views

Where does StartSSL generate the cerificate, server or client-side?

I.e. do really only I have the private key or do I have to trust that StartSSL (or any other provider) don't store it themselves?
4
votes
1answer
13k 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 = ...
6
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2answers
793 views

How can you securely generate keys on AWS?

Our application needs to generate secure keys for long term storage on AWS using openssl. But I've seen some instance where entropy falls dangerously low on AWS machines and this doesn't appear to be ...
2
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3answers
223 views

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?
7
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1answer
143 views

Is a 43 character GPG (symmetric) passphrase as secure as a 256-bit key?

A 43 character securely randomly generated mixed case alphanumeric password (with 2 extra chars to give 64 possibilities per character) would constitute 258 bits of entropy (6 * 43 = 258). Since the ...
2
votes
1answer
110 views

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, ...
2
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3answers
884 views

What is the recomended algorithm to create a key from a password?

In my new secret document encryption utility, the key for symmetric encryption = the hash of a random salt and a user provided password. It is necessary to have a slow hash function in order to ...
0
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2answers
861 views

Which default encryption does OpenSSL use?

If I create a private key via: openssl req -x509 -newkey rsa:2048 -out cert.crt then OpenSSL writes the private key to the file privkey.pem and if you do not provide the -nodes parameter it will ...
9
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1answer
2k views

HKDF and key stretching

I thought that all key derivation functions would do a key stretching phase, by iterating some kind of process. But I can't see that process in HKDF. HKDF doesn't do key strengthening? If I have a ...
5
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2answers
3k views

TrueCrypt and Keyfiles hidden among 500,000 other .pdf files

A question from a newby: I have a USB or Standalone HardDrive with a TRUECRYPT hidden partition on it that needs one or more "keyfiles" and a password to access. What tells the attacker what kind ...
4
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3answers
354 views

Could using a generated key from an online service be considered a risk?

With some colleagues we're having a debate regarding the randomkeygen.com website. I do think that there is a security risk using the generated keys of this (or any of this kind) website. Why ? ...
3
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1answer
89 views

Should I revoke & regenerate PGP private keys after computer is serviced by Apple Store?

I recently had an issue with my MacBook where it wouldn't boot. So I took it in to the apple store, and they said that they would need to send it off to a service center to diagnose and repair it. I ...
3
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1answer
362 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 ...
2
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4answers
2k views

SSH: reusing public keys and known-man-in-the-middle

Usually, people recommend to use a single private-public key pair everywhere (if we're not talking about a possibility of compromising the private key): Best Practice: “One per-user ssh key” or ...
2
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4answers
3k views

Does a renewed certificate open old messages?

I have a digital certificate that I use to exchange messages with peers, my certificate expiration date is due next year, suppose I renew this certificate before it expires, will I be able to open the ...
1
vote
1answer
181 views

Security without TLS certificates

after getting an answer to Security over multi-streaming such as SCTP i have found that i do not have the capacity to give a public key or certificate to the other end securely (to be sure MitM cannot ...
1
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1answer
2k views

ECC Public Key length differs from bit representation

A 256 Bit ECC key-pair (256 Bit is supposed to be the length of the public key) generated with OpenSSL using this command from the manual: openssl ecparam -name secp256k1 -genkey -noout -out key.pem ...