RSA is a common public key algorithm, which can be used for encryption and signature. It is a core component of most the security protocols used on the Internet, including the SSL/TLS protocol suite.

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Trying to understand RSA and it's terminology?

I get the gist of RSA but I'm mostly self taught so sometimes the phrases I picked to describe something don't match up with the widely accepted terminology. I'm trying to remedy this. I'm working ...
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5answers
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RSA maximum bytes to encrypt, comparison to AES in terms of security?

What is the maximum number of bytes for encrypting a plaintext message using RSA that is reasonably secure and also efficient and would AES be better for the same size in bytes? The encryption doesn't ...
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4answers
6k views

Why does PGP use symmetric encryption and RSA?

Looking into the details of Pretty Good Privacy, I'm confused as to the reasoning behind encrypting the message with a session key and the key with the recipient's public key via RSA. I fail to see ...
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2answers
934 views

RSA key recovery using sound - How does it work?

A very interesting Debian security advisory was released yesterday. Genkin, Shamir and Tromer discovered that RSA key material could be extracted by using the sound generated by the computer ...
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1answer
179 views

Managing keys generated with insufficient entropy

Since the Linux RNG which provides /dev/random (and by extension /dev/urandom) is seeded by "mouse and keyboard activity, disk I/O operations, and specific interrupts" (source, PDF) and since virtual ...
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1answer
731 views

Are there any holes in this security design?

This design is for transport security between a client and a server. I'm planning on using it for a cloud storage system. I would like it to be secure against you-know-who. I'm trying to prevent the ...
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3answers
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Is there any particular reason to use Diffie-Hellman over RSA for key exchange?

I often see RSA being recommended as a method of key exchange. However, the Diffie-Hellman key exchange method appears to be secure as well. Is there any considerations one should take into account ...
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4answers
5k views

When should I use symmetric encryption instead of RSA?

I'm currently using GPG RSA keys to encrypt binary files. Many people recommend using symmetric keys to encrypt large files, and then encrypt the symmetric key with a public key. At what file size ...
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2answers
2k views

Web & insecure HTTP - Using RSA for encrypting passwords on the client side

I used client side password hashing in my register and login project. Its purpose is to prevent passive adversaries/eavesdroppers from discovering users' plaintext passwords when HTTP requests are in ...
3
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2answers
711 views

For DHE_RSA_.. Cipher Suites what is RSA used for?

In addition to achieving PFS with DHE, we want as little as possible to be revealed when the server's private key is revealed. So, what is RSA used for in DHE_RSA cipher suites? What does the server ...
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2answers
3k views

What's the limit on the size of the data that public-key cryptos can handle?

Someone mentioned here that asymmetric encryption might not be appropriate for bulk data and gave an example of RSA with 100 bytes. Of course, I understand that it was a rough example. But it made me ...
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1answer
134 views

RSA private/public keys

Is it possible to recover a private key, given a public key and a substring/a part of the corresponding private key?
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1answer
472 views

Does the NSA X-Keyscore apply for HTTPS traffic? [closed]

See X-Keyscore: NSA tool collects "nearly everything a user does on the internet". http://www.theguardian.com/world/2013/jul/31/nsa-top-secret-program-online-data Does anyone have a clue how they ...
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3answers
264 views

Using a stolen certificate on a server

Yesterday I asked the following question regarding what would happen if you placed a stolen certificate on your own server and edited the 'host' file so that the DNS name matched: Could a stolen ...
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2answers
210 views

With RSA, can one ensure that two entities will not have the same private key?

With the RSA encryption algorithm, is there any guarantee that two different entities will not be given the same private keys?
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2answers
558 views

How do openvpn/easy-rsa generated keys map to RSA algorithm variables?

I was reading up a little on openvpn and pki infra and am confused by some of the questions posed by my colleague. :) This answer did help me understand more: ...
11
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1answer
368 views

Recommended operational security for generating one's primary key pair?

I have been looking for an operational security guide for generating one's asymmetric key pair for (Open)PGP. I have found plenty of technical guides for how to use GnuPG to generate RSA key-pairs, ...
5
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2answers
15k views

Decrypt from cipher text encrypted using RSA

I am sniffing a client side application traffic and I found some encrypted data. I am not able to decrypt it. Information which I have is Public Key: ...
9
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1answer
5k views

How does SSH use both RSA and Diffie-Hellman?

SSH protocol 2 allows you to use DSA, ECDSA, ED25519 and RSA keys when establishing a secure connection to a server. (Keep in mind for this question that I'm only familiar with the procedure and ...
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2answers
1k views

Does it matter which key is considered private and which public?

Mathematically, is there a difference which set of characters is private_key and which one is public_key? @Edit At the moment of asking I was thinking on RSA, not asymmetric crypto in general.
4
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1answer
12k 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 = ...
4
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2answers
363 views

Prevent DOS against RSA authentication

In my current setup, the clients are bundled with the server's public key. The client encrypts a nonce and sends it to the server which uses its own nonce and the nonce received from the client to set ...
4
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2answers
2k views

Converting ECC Private key to PKCS#1 format

Is there any way to convert an ECC private key to RSA PKCS#1 format? I have tried converting it to PKCS#8 first using OpenSSL: openssl pkcs8 -topk8 -nocrypt -in EC_key.pem -out pkcs8_key.pem This ...
3
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1answer
2k views

Is the standard scheme of RSA CCA and CPA secure?

I'm looking through old tests in an information security course - and there's a question about CCA and CPA security of RSA. I can't seem to grasp how I'd either show insecurity or prove the security ...
4
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1answer
406 views

Public keys without the certificates

There are two clients and a server. Each client generates an RSA key pair and uploads public key to the server. The server associates the public key with the user identifier that is specified during ...
2
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1answer
404 views

Using RSA for Web Application Authentication

I have a network that is only accessible through bastion servers over ssh. In it, I am developing web applications that are exposed to end users via GUI's served up over websockets. All traffic into ...
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1answer
2k views

Help to understand secure connections and encryption using both private/public key in RSA?

I just started teaching myself cryptography, I am reading this http://www.garykessler.net/library/crypto.html to understand the basics. I am confused by Sections 3.4 and 5.3. Section 3.4 details how ...
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1answer
498 views

Does RSA encryption always pad small amounts of data to some larger size?

If I encrypt 160 bits (20 bytes) of data using an RSA 1024 private key, will the result always be 128 bytes? This seems to be the case in my experiements, but I want to be sure. For example, ...
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3answers
952 views

Is it possible to wrap and export RSA private key in FIPS 140-2 Level 3 compliant hardware?

I would like to do the following on FIPS 140-3 Level 3 certified cryptographic token using PKCS#11: Generate RSA key pair on token Import AES key from multiple components Wrap and export RSA private ...
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2answers
131 views

Why RSA signatures based on the hash of the message? [closed]

Why RSA signatures based on the hash of the message rather than the message itself?
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3answers
3k views

RSA key length vs. Shor's algorithm

I have just read a passage in Zeilinger's book about quantum world. My question is: Suppose there exist quantum computers. Given that a quantum computer can use Shor's algorithm, what key length ...
5
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1answer
3k views

Is TLS 1.0 sufficiently secure for a bank?

I disabled SSL2 and SSL3 in my Firefox browser, version 24. I only enabled TLS 1.1 and 1.2. Unfortunately when I went to my bank's website, I found that it didn't work until I re-enabled TLS 1.0. ...
4
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1answer
594 views

generating RSA keys through the browser

HTML5 has the element that sends an SPKAC to the server (as I understand it). But how do you do it in IE? One CA's websites gives me the following prompt: This Web site is attempting to perform a ...
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2answers
140 views

Isn't this the same as using a certification authority?

Taken from Wikipedia, here is the pretext to my question: A certificate authority (CA) is an organization that stores public keys and their owners and every party in a communication trusts this ...
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1answer
116 views

Is it safe to use private key encryption for lots of small blocks of data themselves?

I currently handle small JSONs of sensitive information which are guaranteed to be smaller than 100 bytes. You can encrypt up to ~500 bytes with a 4096 RSA key. Is it safe/secure to store these ...
2
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1answer
815 views

RSA Possible Vulnerability?

Given c1 = cipher text of m encrypted with n1 and e Given c2 = cipher text of the same m encrypted with n2 and the same e, Is it possible to figure out either of the n's or m? I can't seem to solve ...
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1answer
799 views

How ECDHE is signed by RSA in ECDHE_RSA cipher

About ciphers that use ECDHE as Key Exchange and RSA as Authentication: How exactly this two algorithms work together, is ECDHE process encrypted by RSA public key? What are the DH parameters? ...
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1answer
49 views

How does RSACryptoServiceProvider generate keys

The documentation for the constructor for RSACryptoServiceProvider states "If no default key is found, a new key is created. This constructor creates an Exchange key pair suitable to encrypt session ...
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1answer
545 views

Where is RSA Digital signature used in the online banking world?

When i do online banking, i sign my digital transaction with a digipass. Ive been told that it uses a RSA-based digital signature scheme. But an rsa digital signature (1024 bit for the modulus) is a ...