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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RSA for authentication?

Is it possible to use RSA public and private keys to authenticate two computers (or to make sure they're both the right computers)? If so, how? Thanks!
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Security weaknesses in using RSA encrypted MD5 hash of certificate content

Suppose you have an Internet banking site based on a secure web server running the HTTPS protocol via port 443. The server authenticates itself to clients through an X.509 certificate signed by a ...
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383 views

Share and store RSA - public key in java server and vice versa

My requirements are: Requirement 1: Share public key to java server. Steps: Generate public-private keys in iOS app. Store the generated keys in keychain. Send generated public key to java server. ...
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1answer
172 views

Javascript client side image decryption, does this add any safety or is it flawed

I want to store passport copies safely in a database, the database itself is a normal MySQL database and on a somewhat trusted web server. The user who owns the passport copy should only be able to ...
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3answers
640 views

Why is RSA decryption slow?

I've been researching the disadvantages of using RSA for encryption, and one I've found repeatedly is that RSA decryption is slow, but I haven't seen an explanation as to why this is. Can anyone ...
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1answer
196 views

Most popular RSA key format

We are trying to decide on which RSA key format our application should use. The ideal format would be widely used and supported in most of the popular platforms/frameworks. This would make it easy for ...
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4answers
365 views

how secure is rsa encryption for a web login without https?

I have a server running rstudio. This is basically a web application, and it is currently only accessible over the local network. The web app takes your Linux username/password in order to log you ...
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Can I determine a private key given the encrypted data and corresponding cleartext?

If I know that Data A is an encrypted form of Data B is that sufficient information to determine the private key?
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1answer
170 views

How to fix this broken crypto protocol?

I am considering a protocol where you upload a one time pad to a server, using public key encryption and then the result (using the pad) is sent back in plaintext: Alice uses Bobs RSA public key to ...
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114 views

RSA 4096 key size difference - “sig” and “sig 3”

Whenever I generate a new 4096 RSA key in my GPG program and export the public key to a text file, I get a text file containing a total of around 52 lines (it varies, one of them is 53 lines). ...
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2answers
511 views

Are RSA 2048, ECDSA, and the SHA uncrackable in the sense that AES-256 is uncrackable?

The answer http://security.stackexchange.com/a/25392 has seemingly shown that AES-256 will not be directly cracked for at least the next 200 years (unless we manage to harvest the energy output of ...
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81 views

Can the device seed be recovered from the iPhone/Android RSA SecurID app?

The Windows RSA SecurID app allows the device seed to be determined and cloned from one machine to another (see this blog post). Do either the iPhone or Android RSA SecurID apps suffer from the same ...
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1answer
32 views

Does methods such as Generalized Mersenne are safe way to find p and q? [closed]

There are many methods for finding very large primes fast. Most of them have complete lists. Is it possible an attacker try to guess that p or q was generated using a such kind of method? If yes, ...
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1answer
289 views

OpenVPN seamless migration from 1024-bit RSA to 2048-bit RSA keys

The company I work for has a few OpenVPN servers used by over 200 employees. The servers were deployed a few years ago using the default easyrsa settings and now we want to upgrade to stronger ...
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2answers
109 views

If I change any character in a private PEM, should the public PEM be different?

I'm generating a public PEM-format key from a private PEM-format key. I noticed that if I change a few characters near the end of the private PEM that the public PEM generated from the modified ...
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0answers
98 views

Instant Messaging End-to-End

I plan to create an application for secure instant messaging, now I don't know whether or not I want to implement the encryption by myself. This project is also mainly for educational purpose so I ...
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1answer
80 views

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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1answer
263 views

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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1answer
85 views

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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1answer
122 views

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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1answer
132 views

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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2answers
262 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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3answers
191 views

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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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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1answer
2k views

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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121 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 ...
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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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3answers
959 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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1answer
391 views

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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1answer
292 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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1answer
84 views

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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1answer
225 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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1answer
51 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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251 views

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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1answer
856 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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1answer
163 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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245 views

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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3answers
196 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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3answers
230 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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2answers
83 views

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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1answer
88 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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1answer
94 views

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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1answer
249 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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154 views

“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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1answer
503 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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90 views

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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142 views

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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0answers
29 views

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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1answer
299 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 ...
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156 views

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 ...