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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How much time / “entropy collected” should generating a RSA 2048bit keypair take?

The purpose of my question is get an better idea about reasonable amout of time the generation of the RSA public/private keypair should take? To be less vague let me specify the question and define I ...
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list of PKCS7 certificate file extensions

RSA (the company) devises and publishes the public key cryptography standards. In those standards PKCS #7 is a standard which defines how to encrypt and sign messages using PKI. PKCS#7 defines a ...
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is there any 100% secure way for form authentication and sending information from client side to server side over internet pages? [closed]

i think for acquiring 100 % secure data transfer between forms on client side and c# code on server side ? my tools : i use IIS as my server and i wonder how can i reach for latest security that ...
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How does CryptoDefense ransomware encrypt large data with a (relatively) small RSA key?

I recently encountered some news about the recently new Ransomware called CryptoDefense: it uses RSA 2048 to encrypt your valuables and offers the private key for a price. (It's already been solved ...
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How secure is PKCS #12

I need to move user cryptographic identity between several user devices. In the operating system I have only one option: use password-protected PKCS #12 to import the identity to the OS secure store. ...
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Get PGP Private Key from RAM analysis RSAKeyFind

For an experiment, I'm trying to open a 2048-bit RSA encrypted mail on a image. Using this fresh image, I made a memory dump and analysed the dump for RSA keys. Now, several RSA keys have been ...
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159 views

What can I do with private 128 bit AES Keys?

For my studies, I am required to do an investigation on a fictional criminal VMWare image. The image is suspected of participating in DDoS attacks and other illegal activities. On this PC TrueCrypt is ...
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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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Is all RSA encryption now considered insecure? (Notably SSH and SSL)

Some of the leaks which emerged during/after Snowden concerned the fact that the NSA was paying the organization behind RSA a lot of money in order for them to systematically weaken the encryption by ...
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Certificate verified using two different paths

StartSSL has an intermediate certificate that they use to sign their EV certificates: sub.class4.server.ca.pem. This certificate's issuer is shown by openssl x509 to be /C=IL/O=StartCom ...
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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 ...
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115 views

Any alternative available for RSA? Is the web still visible to NSA?

After the Snowden revelations, is there any mass change being carried out to HTTPS protocol? As far as I understood, any HTTPS communication is still visible to NSA as they can compromise the RSA ...
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DNSSEC signing algorithms

Virtualmin supports a flurry of algorithms for DNSSEC: RSASHA1, RSASHA256, RSAMD5, DSA, DH, HMAC-MD5, NSEC3RSASHA1, NSEC3DSA. If I understand correctly, there's Proof of Concept available for SHA1 ...
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Why does the linux XRDP module use a 512 bit RSA key? [closed]

Why does the linux XRDP module use a 512 bit RSA key? 512 bit RSA keys are broken by now. How can this be safe?
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Need help designing an encryption workflow

Background: I'm building a .NET application, a very small part of this application allows for users to communicate with a third party application. I am designing this aspect. The third party simply ...
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49 views

Possible to Derive Private Key from Public Key Given Enough Computing Power? [closed]

Is it possible via brute force to derive a private key from a public key (such as a website's SSL certificate)? If so, how much computing power would you need to make it feasible, compared to say, ...
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54 views

Making a bitcoin-like secure mail protocol, how to tackle public keys?

I'm making a new mail protocol (probably already exists, but I've learnt a lot of things about security and privacy on the way). Here's the summary(much simpler if you know bitcoin's inner workings): ...
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44 views

Timing Attacks in RSA

Considering the classic scenario of Eve trying to listen in to Alice and Bob's conversation, if Eve can intercept messages between Alice and Bob but with no access to their computers would Timing ...
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177 views

How to secure communication between server application and client mobile application through HSM

We are planning to deploy HSM with our application. The solution we are thinking is : Mobile applications talks to server application, Server application talks to HSM for authentications, ...
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72 views

Can anyone explain how to use an X509 client certificate to securely authenticate a user?

Bit of background. Web Application that can generate Pub/Priv Keys and X.509 certificates. How would I make use of the certificate in a web application, username and password login form to provide ...
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Import securely RSA private key through PKCS#11

I have a cryptographic device that supports the following mechanisms: How I could securely import RSA private key into it? Because there is no support for wrap/unwrap using symmetric key is there ...
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149 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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73 views

Is a Diffie Hellman Ephemeral key good material for being used as a symmetric cipher algorithm key?

I am designing a secure protocol (for academic/learning purposes) and I am at the point where I need to (re)design the key exchange step. In my previous implementation, I used to rely on RSA to ...
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101 views

Can RSA keys be swapped?

On a theoretical level, is there anything inherently different about public vs private keys? During RSA key generation there are two keys generated, key A and key B. Key A is private and Key B is ...
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Use the same IIS RSA key on all servers

I am working on standardizing our server builds where we currently have three different functional pools. For web pools I use the same IIS RSA key across all machines. It keeps life easy and ...
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Where to offer money for cracking check [duplicate]

I made a software and I would like to distribute it as a demo that can be registered. I would like to know if there is a site where I can offer some reward for some one try to crack my software and ...
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54 views

Theoretical key encryption question

I have a question regarding encryption and message sending. There are 2 hosts, A and B with their own secret key kA and kB (assuming this is not PKI). It is known that when A wants to send a message ...
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“Keyset does not exist” when using SignData function with RSA

"Keyset does not exist". I know that there are tons of question about this error, but mine is totally different. I'm not gona use the key from windows certificate store, but load the public key & ...
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123 views

Questions about RSA/asymmetric key encryption?

I've been reading a lot about quantum computers and RSA. I know RSA security relies on the difficulty of factoring an extremely large number with just two prime factors. Apparently quantum computers ...
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125 views

Convert RSA SSH public key file into x509 certificate

I have a RSA SSH public key which I have converted from a x509 certificate and I want to be able to convert the SSH key back into a x509 certificate to compare the values with the original ...
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RSA key exposure

Is there any limit to the number bytes that an RSA key can be used before it can be exposed. In Symmetric encryption a Key is not recommended to be used to encrypt more than specific amount of data ...
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Is my approach to anonymous certificate based HTTP(s) authentication and secure private messaging sound?

I'm trying to work out a somewhat anonymous secure messaging system, and was hoping someone could validate my overall approach. Keep in mind, this all takes place over HTTPS. Authentication While ...
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1024-bit DHE vs 2048-bit RSA

Currently with apache/mod_ssl, if DHE is enabled then a 1024-bit ephemeral key will be used. I found the following quote in Adam Langley's blog: Ideally the DH group would match or exceed the RSA ...
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Secure data with server and RSA? [duplicate]

the RSA system uses a private key to read the content encrypted with the public key. If I make a game for mobile, and want to save the data : I guess I cannot save the private key on the device. If ...
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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 ...
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What is the excellence of RSA vs my algorithm [closed]

I was wondering that what make RSA Asymmetric Cryptography Algorithm special. So I wrote a very simple algorithm that do the same work (Generate Public and Private Key) Now I want to ask you that What ...
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RSA encryption confidentiality [closed]

In this scheme , is confidentiality guaranteed? A sends to B an encrypted file which is encrypted by B's public key. Can you illustrate any variant, still RSA- based but also using symmetric ...
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197 views

Does ciphersuite ECDH / ECDHE need hardware acceleration

I have started to read more about ECDH/ECDHE and am wondering if it has the similary issues as RSA - i.e. the processing power required for the decryption of private key is more than of the public ...
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Why should the dh keylength match rsa length in tls?

A few sources state that the DH keylength (bits of the prime) should match the keylength of rsa for TLS. For example SSL_set_tmp_dh(3) from openssl has example code on how to match the dh parameters ...
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183 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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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 ...
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Which part is the longest when gerating RSA key pairs?

Whether I use openssll or gnutls's certtool, I end in a single threaded part which take several minutes. When I try to compile the libraries with auto-parallelizer advanced efficient tools. It sill ...
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351 views

Look over my Web API Authentication Scheme

I want some advice on my Authorization/Authentication scheme that I will be using for my Web API that I am writing. Firstly the Authentication : 1) When a user first logs in and they are authorized, ...
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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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encrypting a file with an RSA key

I wrote a java program to encrypt and decrypt files using AES algorithm in CBC mode and a random initialization vector. but there is something fundamental I'm not understanding:first I generate a ...
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Broken/halfbaked security with this implementation?

I'm reading the specification for a commercial product which provides a webservice.The spec goes like this: The client (a webbrowser) may use https Client asks server for info --> gives modulus and ...
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263 views

Authenticate user without knowing their password

I'm working on a project where each each user will have a public/private RSA key-pair. Users will be able to send encrypted messages to each other using the each target user's public key so that only ...
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4answers
345 views

How can we trust PKI, for example, Verisign?

We want to send an encrypted message to Alice. We can ask her a public key over the network, encrypt with it a message and send that message back. It is bad, because someone can pretend to be Alice ...
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668 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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Is generating an RSA key with password and then stripping it off more secure than no password at all?

Some time ago I came across this question on SO; it asks how to remove the passphrase from an existing RSA key using a PHP equivalent to the existing openssl rss command. I've posted an answer with ...