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.

learn more… | top users | synonyms

2
votes
1answer
206 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 ...
0
votes
2answers
299 views

Using given RSA private key without the associated public key

I'm currently following a small game to get more familar with linux and security and got the following task: The password for the next level is stored in /etc/bandit_pass/bandit14 and can only be ...
1
vote
0answers
22 views

Recommended Crypto Security Setup (Implemented Algorithms)?

Firstly I'm not a crypto expert, however I know how to use algorithms that other people have defined before in practical usages, that is, as long as they live up to their promises. The thing is that ...
0
votes
2answers
76 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 ...
1
vote
0answers
50 views

RSA-1024 vs. DSA-1024: Claim DSA SSH key is much faster to brute force

Does the brute force speed vary significantly between 1024-bit RSA and DSA SSH keys? DSA like gpu keypairs are probably DSA/Elgamal? (Can't find docs) EDIT: The reason I ask is an instructor that "...
1
vote
1answer
36 views

Non-identified algorithm for RSA decryption in tpm-emulator

While analyzing the source code of tpm-emulator I found that the RSA key decryption uses an algorithm that is unknown to me. The original file with this mystery is located in rsa.c, where the ...
-1
votes
0answers
31 views

Encrypting the data in C# using Java generated RSA key (public) [on hold]

Need urgent help on how to encrypt the data in C# by using JAVA generated RSA public key. PFB the information to be used as reference. Public Key: ...
0
votes
2answers
36 views

Can an RSA signature be changed given the public key?

If I were to post on a forum (with potentially malicious administrators) my public RSA key and a small string of text that was signed with the corresponding private key, could someone with access to ...
3
votes
3answers
288 views

How does a chosen ciphertext attack work on textbook RSA?

I am very new to cryptography and I am confused with something. Here is the homework question I am having trouble with: Write a program to attack the Textbook RSA Encryption Scheme, in order to ...
6
votes
1answer
117 views

Manually walking through the signature validation of a certificate

Since I am not too familiar with the Web of Trust and Public Key-Infrastructure I decided to learn about it by following the signing chain of a X.509 certificate issued to CN=*wikipedia.org (Serial ...
7
votes
1answer
312 views

Using ECC for PGP-Master Key in combination with Yubikey

I acquired a Yubikey Neo last month. Now I want to use the Smart-Card functionality for PGP. I followed the official guides on the Yubico Website tested it with 2048 RSA Keys and it worked fine. But ...
4
votes
1answer
85 views

Ways to generate symmetric and asymmetric keys

We are using Beaglebone Black based custom board, and want to use hybrid encryption for encrypting firmware file, i.e. symmetric for encryption big firmware file and asymmetric for encrypting ...
4
votes
1answer
142 views

Should SHA-1 be used with RSA-OAEP?

PKCS#1 defines SHA1 as a 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 ...
1
vote
0answers
17 views

Should SHA-1 be used with PKCS #1?

I came across this excellent question and answer: Should SHA-1 be used with RSA-OAEP but it only covers RSA-OAEP. RSA-OAEP is not the only place in PKCS #1 where a hash function is used. Should we ...
0
votes
1answer
26 views

Is it safe to generate JWTs using private key?

Currently I'm building a Rails API using ruby-jwt as my access token generator. I choose RS256 (RSA + SHA256) as my algorithm. ruby-jwt uses private key to encode payloads, and uses public key to ...
1
vote
1answer
136 views

Which file encryption algorithm is used by Synology's Cloud Sync feature? [closed]

I'm trying to find out which encryption method is used by a piece of software I use, viz. the 'Cloud Sync' feature of Synology's DSM 6.0 running on a Synology NAS. (Background. This Cloud Sync ...
-4
votes
1answer
100 views

Preventing someone to generate a public key from a private one? [closed]

From what I read, encryption algorithms such as RSA permits to generate the public key from the private one. Long story short, for a thesis I'm writing, I thought to solve a security issue with users ...
0
votes
0answers
10 views

Does PKCS 1.5 padding make it possible for an attacker to extract the private key or not? Is PKCS 1.5 safe to use in authentication context?

Im currently writing a authentication app based on RSA, for Android that should be impossible to copy, even if you have physical access to a phone without lockscreen/PIN. However, the HSM inside the ...
0
votes
1answer
100 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 $ ...
0
votes
1answer
61 views

Storing sensitive, sharable data

I'm building a intranet solution for a company using PHP. One of their desired functionalities is storing payrolls, absence and personal information. They need this to be accessible for the employee ...
14
votes
3answers
5k views

How do RSA SecureID ® Keys Work?

I have been using RSA SecureID ® Keys for quite some time now (perhaps 10 years), for things such as securely my home banking account online or accessing my company's network of computers from home. ...
3
votes
1answer
977 views

Why does the linux XRDP module use a 512 bit RSA key?

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?
0
votes
1answer
31 views

Does password protected git public key protect my repository?

When generating my public key for GIT access, I decided to set up a password for it. My push procedure looks like this now: Enter passphrase for key '/c/Users/USERNAME/.ssh/id_rsa': Counting objects: ...
0
votes
1answer
50 views

Crypto++ RSA - Encrypt and sign with the same key pair

I have a program A which needs to send messages to several instances of program B (B1, B2, etc...). The messages must be encrypted, and also signed. Which means only Bn instances can decode, and they ...
4
votes
1answer
68 views

Why use a passphrase for RSA key?

Today I generated my first key pair, so my knowledge here is - so to speak - very limited. On client side I am using Windows and to log in I use PuTTY and I used PuTTYGen to create the keys. Here (...
1
vote
0answers
45 views

What is the largest cycle of RSA encryption?

Is there a maximum length of a message before it is impractical to use RSA?
0
votes
1answer
110 views

Why doesn't my manual RSA key exchange example work?

I'm trying to "manually" compute how the premaster_secret is computed using the RSA key exchange in TLS 1.2, but can't manage to make numbers meet. I am using Scapy SSL to generate a TLS session: I ...
0
votes
1answer
169 views

Is this algorithm really end to end encrypted and secure?

I'm creating an anonymous chat where one of the premises is that the conversations are end to end encrypted. I'm using firebase so all the comunication between the clients and the server is SSL ...
0
votes
0answers
26 views

Clarification of RSA Key Exchange (TLS 1.2) and AES for On-Going Message Excahnge

I'm trying to understand the full flow of key exchanges for secure communications. As a potentially incorrect premise, I am under the impression that RSA is a good asymmetric technique for ...
0
votes
0answers
50 views

JSON Web Token Security RSA

We are planning to use JWT (JSON Web tokens) in an application project, which is a set of multiple distributed web services allowing SSO authentication (single sign on). So there is a single central ...
0
votes
0answers
15 views

Is it ok to use one key pair for my authentication endpoint?

I have an web endpoint that checks user passwords, then issues signed JWT tokens to the client if password matches what we have in the database. The JWT is signed with a RSA private key using RS512. ...
1
vote
1answer
223 views

Is using “SHA-256 with RSA-2048 Encryption” a secure certificate hashing algorithm?

Is using "SHA-256 with RSA-2048 Encryption" a secure certificate hashing algorithm? I don't think it is. Two examples: nsa.gov [careers site] give.wfp.org
2
votes
1answer
114 views

What is the difference between a digital signature and whole message encryption?

I am newbie in information security I am trying to understand the difference between a digital signature and encryption of a message. Lets consider simple example of email message. I understand how ...
2
votes
2answers
520 views

PKCS#1-1.5 encoding - is there a reason to use 00 in block type?

For encryption block looking like this: EB = 00 || BT || PS || 00 || Data where BT - block type and PS - padding string, I've read that we use three types of BT - 00, 01, 02. Now, since 00 and 01 are ...
0
votes
0answers
27 views

Using the same public exponent for RSA on multiple machines

I have a system where many machines running the same software work independently of each other with no central server of any kind. A user may wish to speak with another user privately and securely, ...
9
votes
5answers
3k views

Is this RSA/AES combination good?

The team of developers I am part of is trying to develop a safe way to exchange sensitive data between a server and mobile devices. We have come up with the following algorithm: Device generates ...
2
votes
1answer
770 views

Determine private key size using public certificate [duplicate]

I have a public certificate in a PEM (.pem) file -----BEGIN CERTIFICATE----- MIICsjCCAZqgAwIBAgIJAMA1YIQ2JLXDMA0GCSqGSIb3DQEBBQUAMBExDzANBgNV ... 29V/R9RZOoSBHDzGPL84wm4qojMuwQ== -----...
0
votes
1answer
33 views

Verify a key was signed by another key

I began using GPG4Win/Kleopatra, the GNU Privacy Guard implementation for Windows. More recently I wanted to verify a download of Qubes OS, for which a guide is offered here. They describe a master ...
6
votes
1answer
263 views

Are RSA Key Pairs unique?

I generate RSA key pairs mostly using the following command: ssh-keygen -t rsa -b 4096 -C "someemail@hostname.com" which produces a public-private RSA key pair. If I run this command again and ...
2
votes
2answers
165 views

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 ...
9
votes
1answer
7k views

New PGP key: RSA/RSA or DSA/Elgamal?

I wanted to create a new PGP key using GPG Keychain Access on my Mac. One of the options was to choose keytype: RSA and RSA DSA and Elgamal RSA (Sign only) DSA (Sign only) I found this Superuser ...
5
votes
2answers
650 views

How much faster does a GPU or FPGA crack an RSA key compared to a CPU?

Are there any significant speed up in time on cracking an RSA key (either brute-force or factoring with general number field sieve) using a GPA or FPGA compared to a CPU? If there is a speed advantage,...
1
vote
1answer
110 views

Someone logged in server through ssh using my RSA key

I just got the warning message from hosting provider that my server make outcoming traffic 1.5G to provide DDOS attack on someone host, and they disabled my VPS temporarily. When I search through ...
16
votes
2answers
2k views

Is it bad that my ed25519 key is so short compared to a RSA key?

I recently generated a new SSH key in the ed25519 format. The public key is only 69 bytes long while my old RSA key is 373 bytes. From my perception ed25519 is the more recent and secure format. So ...
0
votes
0answers
26 views

Why SMIME decryption works with sender and recipient private key?

Im developing an application, that needs to use SMIME encryption and authentication. I've implemented a decryption system, and am currently testing it. I send the emails with another fully working ...
3
votes
1answer
69 views

Is this good/secure method for client-server communication encryption?

Something came to my mind, and I wonder if this is proper method for client-server communication, and if this method is wide-used. On connection, client generates seed, encrypts it using asymmetric ...
-7
votes
1answer
95 views

Is webkey a reasonably secure authentication system?

I just created Webkey in the last couple days. It's built to do client-certificate auth without using the (in my opinion unusable) client-cert functionality built into browsers. It would allow single-...
2
votes
2answers
183 views

Is the RSA private key useless without the password?

I notice whenever I generate a new gpg key (using pgp) I always have to assign a password to it, which makes perfect sense. But if I'm not mistaken, gpg is based on prime numbers. How is this ...
0
votes
1answer
2k views

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 CA....
0
votes
0answers
19 views

Signature algorithm with ECDH ? can we use RSA or ECDSA ? or ECDSA is compulsory?

I am going through RFC 5656. I want to know if ECDH with RSA is allowed? (I am not SSH ECC compliant).