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 to decrypt it on RSA encrypted message? [on hold]

You must decrypt the following RSA encrypted message, the thing is you only got public key :/ which is as following ...
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1answer
72 views

Questions on the variations of RSA keys

I've built a simple application that reads in an RSA key, checks the header and starts identifying properties of the RSA key to make sure it is valid (Using child_process in express to run $ ...
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27 views

Is this c# digital signature implementation secure?

The code connects multiple clients to a server using TCP sockets asynchronously. I have added code to attach a digital signature to the outgoing messages from the server, to authenticate the message ...
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1answer
43 views

How can a RSA-2048 certificate be vulnerable to logjam attack? [duplicate]

Most likely I am missing some fundamentals: Our web servers are secured with TLS encryption. We use RSA-2048 bit certificates. The logjam attack targets the DH algorithm. How can our web servers be ...
3
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1answer
31 views

Should SHA-1 be used with RSA-OAEP

PKCS#1 defines SHA1 as default Hash function and all implementations support this Hash function and the Mask generation functions based on SHA1. In some implementations you can change the Hash ...
4
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1answer
48 views

What does an OpenPGP signature consist of?

I don't understand how OpenPGP signatures work. I have a picture which I want to sign, and a digital certificate which consists of my name and email address and my public key. Additionally, a digital ...
2
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1answer
107 views

Strange RSA usage - how secure is it?

Is following communication scheme secure? To my mind, it uses RSA modulus and public key exponent as a cryptographic secret, which is strange usage of RSA, but can it be easily broken because of ...
3
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1answer
134 views

How do I find a PKI smart card reader/writer for development (Microsoft .NET)

I would like to learn how to develop software leveraging PKI smart cards. Ideally, I would use Microsoft Base Smart Card CSP, but I really just need the ability to store symmetric and asymmetric keys ...
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2answers
27 views

Self-chosen fixed RSA PIN in addition to a Password

I'm using a Junos Pulse Secure Access Service (Juniper Networks), which requires to enter a RSA PIN in addition to the password. I don't know if this is always the case or if it's a custom ...
0
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1answer
28 views

Authenticating a user by verifying a signature

Background I'm setting up an API which will be used primarily over HTTPS (only calls not needing any security what so ever is available over HTTP). Some aspects of it need to be accessed only by ...
5
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1answer
391 views

Encrypt in C# program, Decrypt in android application By RSA Keys

I use RSA encryption for sending messages between a server and client. The server program is implemented in C# and the client is an Android application. I want to know if it is possible for a ...
3
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1answer
24 views

Is it possible to have an RSA authentication subkey with a DSA master key?

My key setup is as follows: sec dsa3072/CA72E53A created: 2013-05-12 expires: never usage: SCA trust: ultimate validity: ultimate The following key was revoked on 2016-01-13 ...
3
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2answers
222 views

Was DSA invented from RSA?

I'm wondering if the two algorithms are similar and whether DSA was really just based off RSA? Is DSA based on RSA and public key encryption? If so how does DSA introduce signing and makes it ...
3
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2answers
91 views

How to counter the security risks of shared prime factors among RSA moduli employed in practice?

A. K. Lenstra et al. in an extensive examination of the RSA moduli employed in practice (http://infoscience.epfl.ch/record/174943/files/eprint.pdf, p.10) wrote that they "could not explain the ...
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2answers
32 views

RSA blind signature vs signing a hash

My understanding is that the key feature of a blind RSA signature is that the signer is unaware of the contents of the message being signed. How is this different from simply hashing some data and ...
2
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1answer
48 views

Licensing system for client side code web application

I have a client-side web application running on SharePoint Site Collection, each site collection has it's own unique id. I want to use a licensing process to lock the app to a site collection. This ...
3
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1answer
412 views

ECDSA/RSA certificates and cipher selection

In this image can someone tell me if a standard RSA certificate can support the EC*_RSA ciphers listed? If so do you create the typical RSA keys when you are creating the CSR? Also I am fairly ...
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0answers
26 views

Can there be two certificates with a same serial number in the world? [duplicate]

Recently I came across this odd question. I hope, Serial number is unique across certificates signed by a particular CA. So is there any chance that two different CAs sign two different certificates ...
4
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2answers
132 views

Passwordless website authentication scheme

I have a userbase which really isn't all that inclined to create a secure password for a website. They're also almost entirely on mobile devices, so I would like to try something a little different ...
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37 views

CMS signed data OpenSSL verification error

I have a CMS signed data that is successfully verified through Java BouncyCastle library. When trying to verify through OpenSSL, I am getting the following error: >openssl smime -verify -inform ...
3
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2answers
2k views

RSA public key and private key lengths

I'm having a problem understanding the size of an RSA public key and its private key pair. I saw different key sizes for RSA algorithm (512, 1024,... for example), but is this the length of public ...
2
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0answers
41 views

Why is DSA is faster than RSA for signature generation but slower for validation?

Almost on every post comparing DSA and RSA, I see a point brought up: DSA is faster for signature generation, but slower for validation. I wonder why this is? For example, in DSA, to sign something, ...
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1answer
41 views

How to use RSA private key for TripleDES encryption?

Our goal is to send SOAP messages to a web service, signing these messages using TripleDesRSA15 algorithm. Web service staff sent us a .pfx file, where certificate for encryption is stored. I'm able ...
3
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2answers
85 views

Encryption in peer to peer chat

For a homework assignment I'm developing a chat service that will be able to communicate within a single network. The communication channel should be encrypted with RSA. Should I generate keypairs ...
2
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2answers
77 views

Is this a secure Digital Signature + Encryption method?

I am trying to wrap my head around Digital Signatures and how RSA Encryption supports them. And which order to do them along with what specifically to encrypt. So say we have Alice and Bob and a ...
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34 views

On the Import Client Key screen in Bitvise what is numeric field just next to the Location Profile dropdown?

What is this field for? I know I saved a profile in the beginning, and I want this private key to be attached to just the profile that I'm using, but what on earth is that numeric field for?
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1answer
30 views

Is D parameter of the RSA strong enough to be used as secret for HMAC calculation?

Short question: Is the D parameter of the RSA alghorithm crypthographically strong enough to be used as a secret key for generating SHA-256 hash value? Long question: I'm working on windows platform. ...
0
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1answer
45 views

What effect would removal of RSA tokens from mobile phone have on surveillance? [closed]

Reading the comments at Bruce Schneier's blog, I came across this recommendation by someone where they write: @Michael_H - Here you go, buy yourself a cheap Huawei G6620 on eBay, any network, ...
4
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2answers
184 views

Why did browsers deprecate 1024-bit RSA, but retain SHA-1?

I was reading Mozilla's security blog Phasing out Certificates with 1024-bit RSA Keys. Effectively, some browsers are deprecating 1024-bit RSA for CAs and Subordinate CAs because the certificate must ...
0
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1answer
67 views

Generate RSA2 key in OpenSSH format in windows

I have to generate a key, RSA v2 in OpenSSH format. I am a bit confused. I am trying to generate it using Putty key generator. There I see an option SSH2-RSA and SSH1-RSA. So is SSH2-RSA the RSA2 key ...
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28 views

Storing user private key paraphrase during session

We have a web application which is used to store secrets (passwords, pins etc) and share them to other system users. Currently for encryption we use AES with single encryption key, and all secrets ...
2
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2answers
655 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
56 views

secret key not available for decryption, but still shows up in GUI

I'm trying to decrypt a message using my personal secret key. When I try to decrypt the message (using gpg --decrypt message.txt), I get the following error: gpg: encrypted with RSA key, ID 3810D17A ...
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4answers
5k views

Why is key exchange necessary at all?

Let's say "Alice" and "Bob" want to communicate with each other over an insecure network. Using Diffie–Hellman key exchange, they can get the same symmetric key at last. However, as I understand, ...
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3answers
239 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
114 views

RSA: Do private keys have to be private?

I was thinking about using RSA, but in reverse. Where everyone has the private key, and only the server has the public key, so that all the clients can decrypt a message from the server, and the only ...
3
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3answers
476 views

Encrypting USB traffic: Is RSA necessary for AES session key exchange when using pre-installed secret keys?

I need a solution to encrypt USB communication between device A and device B. I was thinking about configuring each device with a secret RSA-2048 key, which would be used to exchange an AES-256 ...
2
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1answer
458 views

RSA/ECB/PKCS1Padding: Encrypting a Session Key JavaScript

How to do ECB mode when dealing with RSA? I dont understand it. The Aadhar authentication doc (http://uidai.gov.in/images/FrontPageUpdates/aadhaar_authentication_api_1_6.pdf Page 33) says that we have ...
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2answers
2k 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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2answers
49 views

RSA and Psuedorandom Number Generator

I want to give a presentation on school about RSA encryption and decryption. I understand the basic of calculating a public and private key with two small prime numbers. And how to use those keys to ...
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43 views

How to decrypt RSA cipher text? [closed]

How can I decrypt an RSA cipher text in which I am only provided with a public key and the cipher text. The person who encrypted it made a mistake in taking the exponent.
4
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1answer
78 views

RSA fingerprint automatic change or have I been hacked?

today I tried to connect to my Digital Ocean VPS through Putty(kitty) as usual, but I got the message that the server's cached fingerprint had changed, and that it could be a security compromise. I ...
5
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1answer
233 views

GPG (PGP) decryption speed issue

We are new to using GPG and we have a very strange issue with decryption speed when using RSA keypairs, which are generated by using different tools (GPG for Windows, DidiSoft OpenPGP Library for .NET ...
3
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0answers
46 views

Could RSA be used as a block cipher?

I always thought that the reason we couldn't use it was because it required too many CPU cycle. But an answer from @TomLeek indicated that this was not the case : ...
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2answers
485 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: ...
4
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1answer
380 views

How is JWT implemented?

I'm using django-rest-framework-jwt in one of my APIs. As you might know, the concept is simple: you send username and password and you get a token back. The token is not stored anywhere on the ...
3
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2answers
69 views

Is it possible to protect a DER private key with a password?

I want to write an API, based on OpenSSL, that can convert an RSA private key stored as DER to the PEM format. I'm just wondering if a DER key can be password-protected. I've searched the OpenSSL ...
3
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1answer
128 views

How can I use my HSM to turn a CSR into a certificate?

I create a CSR using OpenSSL, so I have public and private keys. Now I want to sign this CSR and convert it into an X.509 certificate. The only problem is, my signer is a custom HSM. I can send bytes ...
3
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1answer
51 views

Public-key encryption for pre-shared keys with MAC

What well-known algorithms are suited for the following task? I need system A (and only system A) to be able to encrypt some data, with system B being able to decrypt it. At system B, I want to be ...
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1answer
67 views

Need asymmetric encryption(not signing) where server encrypts and client decrypts

So I'm trying to build a licensing server, where the licenses of the applications need to be checked when logging in or when the application gets used. But some of those application work offline most ...