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 set size of RSA key in aspnet_regiis [migrated]

How do i set the key size of my rsa key. Creating the key: aspnet_regiis -pc "test" -exp -size 4096 Exporting the key: aspnet_regiis -px "test" "c:\myKey.xml" -pri this does not give me key size ...
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Hash file of a .xls file from RSA securID attack 2011 [on hold]

I am very new to information security , i am doing a presentation on RSA hack not a very technical one. I got hash file of excel sheet used in RSA attack in 2011 i got it from virus total but i don't ...
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34 views

Same RSA key pair for all users

Let's say in my computer running Debian i have an RSA key pair generated by user foo and copied the public key to server_A for allowing key based authentication in ssh for foo. Now my question is can ...
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34 views

public key formats [on hold]

I have the following PEM format public key: -----BEGIN PUBLIC KEY----- MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDguwHaldTclMAFg1BQ45Q8DPIc ...
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Decrypting old data from PHP extension

I recently came across an old website of mine that I had used the PageProtectionPlus MediaWiki extension to encrypt parts of. I'm curious to see what I wrote, but the extension is no longer supported ...
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Encrypting short data with RSA only?

I have a case where I need to create recovery accounts and I want to create them so that nobody knows the password to them until/unless necessary. Hence, I thought that I would do it using RSA - when ...
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What ciphers do I need to disable in tomcat to match a specific apache conf? [migrated]

I have instructions to disable weak ciphers in apache by adding SSLCipherSuite ALL:!MD5:!aNULL:!ADH:!eNULL:!LOW:!EXP:RC4+RSA:+HIGH:+MEDIUM to my httpd.conf. I am actually running tomcat, and in my ...
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98 views

Why use anything other than RSA for transmission encryption?

Being fairly new to the cryptography and data security space, I have sampled a few "Introduction to cryptography" sites/textbooks and they all seem to start in the same general way: This is a Caesar ...
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92 views

SSH raspberry pi security

I've setup an SSH server on my Raspberry Pi. I use RSA keys to login, I disabled root login, password authentication and I use port forwarding to login from outside my network. I can see the ...
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2answers
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How can I create my own public certificate using openssl?

I have a public key/private key pair i generated using two primes p and q. I now need to use openssl to sign and create the certificate. I heard req utility and wrote this from the man pages. openssl ...
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What type of encoding do .pem files use to store the key?

What encoding is the modulus in RSA cryptography stored as in a .pem file? Is it something similar to base64 of the modulus? I can retrieve the modulus using the following: openssl rsa -in ...
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2answers
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RSA and AES combination in offline situation

I need to securely request and receive data from a server. The client has the RSA public key, and the server has the RSA private key. So I am generating a random key for AES-128/CBC cipher and ...
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53 views

openSSL selects ECDH-RSA instead of ECDH-ECDSA

I am trying to do a secure connection with openSSL between a client and a server that I wrote. When I try to select the cipher suite to use, I do SSL_CTX_set_cipher_list(ctx, ...
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1answer
703 views

Relationship between RSA, Diffie-Hellman Key Exchange, PKI and X.509?

I am getting confused with RSA, Diffie-Hellman Key Exchange, PKI and X.509v3. I took a look of RSA's mathematics algorithm, it seems like a encryption algorithm, right? Generating public key and ...
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473 views

Strength and length of Symmetric vs Asymmetric keys [duplicate]

There are many questions surrounding the differences between symmetric and asymmetric encryption keys. I think I've read them all at this point. But I'm still left wondering: Why does a "secure" ...
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1answer
47 views

Signature scheme using RSA and SHA512

What do you think about this signature scheme using RSA with 4096 bit keys? Being R pseudorandom padding, fixed length (4096 - 512 bits): RSApriv(R || SHA512(M)) I know that it's not as secure as ...
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RSA generation of private key using public key [migrated]

In RSA private key generation e*d ≡ 1 mod φ e is public, also n is public. How to prove mathematically, generation of private key d is not possible using the same equation and public key e
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3answers
858 views

What is Provable Security? [closed]

In computer security, what does provable security mean? I read the Provable Security article on Wikipedia, and I was able to grasp the basics. I would like to see this described in more detail, using, ...
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1answer
30 views

Obtain X.509 Certificate Fingerprint from Certificate Info

I would like to obtain the SHA1/MD5 fingerprint of an X.509 certificate in order to compare it with the one presented by a server before connecting. However, I currently don't have access to the ...
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43 views

Why does an RSA key (256 bits) have more than 256 bits of ascii characters?

As an example, I generated a 256 bit key pair. The private key (when saved to a file by puttygen) is: AAAAIGZcM73lV3Uk/psErZAYA0F+4xK78FtFoVi2fdypv92tAAAAEQDdOhyFJ6iV ...
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1answer
48 views

SSL over self-implemantation of RSA?

I currently write a client application which communicates with a PHP server. The application itself requires valid user credentials and get all of his information by doing POST requests to the PHP ...
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57 views

Soft tokens - multiple profiles on same smartphone

Some of our clients have started migrating to soft tokens instead of hardware ones for two-factor authentication to their network. We have apps like RSA SecurID and VIP Access on our smartphones. The ...
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1answer
74 views

Why not just pad RSA with random bytes

So, i understand that we should always use padding on RSA so that if we send the same message with different keys, the Chinese Remainder theorem can not be used to decrypt it. When looking at the ...
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2answers
94 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 ...
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191 views

Is an >=2048bit key with Asymmetric encryption secure enough to negotiate a Symmetric encryption key?

Let's say that a client app already knows the public key of the server to which it needs to communicate with and the client app needs to connect to the server using a normal non-secured internet ...
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1answer
81 views

Why should I use easy-rsa when using OpenVPN?

Reading this guide on how to setup an OpenVPN server on a Raspberry Pi, I saw this line: 4) You don’t want anyone who finds your VPN server address to be able to connect. So next, we’re going to ...
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1answer
55 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: ...
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1answer
71 views

Key generation: Differences between GnuPG classic, stable, modern?

I plan to create a 4096 bit RSA&RSA key pair: gpg --gen-key --personal-digest-preferences SHA512 --cert-digest-algo SHA512 Is there any difference in generated key quality between versions 1.4 ...
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1answer
147 views

Use openssl key to decrypt file in android/java [closed]

I want to decrypt file encrypted in openssl in java. File is encrypted with private key using openssl and on java side i want to decrypt it using public key. The code: public void testRSA() throws ...
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1answer
36 views

PKCS12 - private key protection

I know that PKCS12 private key is protected by a password, but what is actually done with the password ? Does it use PBKDF to derive the key from password ? That would be a problem as if you change ...
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1answer
491 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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1answer
126 views

How encryption/decryption of RSA private key by passphrase works?

I would like to know how exactly the encryption of private key by passphrase works. I am a software developer with no background in cryptography and I know only some basics. When I open the private ...
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548 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. ...
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Use of RSA in Yaksha Security System

So I'm reading over the Yaksha Security System and see it is based on the RSA cryptosystem and a centralized server, easy enough. What I'm slightly confused on is the math behind the related keys. It ...
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1answer
74 views

Calculating D-Wave's integer factorization capabilties

D-Wave has teased the ability to perform integer factorization previously, but if you jump to ~10:00 in this presentation they actually appear to outline how they can perform integer factorization ...
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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.
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How is security of server's RSA private key is ensured?

We repeatedly hear news of hacking of passwords from PW database (server side) but nothing about hacking of server's RSA private key (not asking regarding finding p and q for a given public modulus ...
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1answer
71 views

Use of safe prime in RSA digital signature scheme

For the RSA digital signature scheme , Alice has a pair of public and private keys as denoted by Public key : (e,n) Private key : (d,n) Assuming Alice wants to send a message M to Bob , she would ...
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146 views

Sign SSL certificate with root certificate using openssl

I have created a root certificate, My Root Certificate, with a private key, RSA Private Key 1, using the openssl terminal command. I would like to make a certificate chain such as the following: My ...
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50 views

What are the compatibility implications of generating a new TLS key?

The guide I'm following says to use openssl genrsa to generate a TLS key, which I did. I've changed the CSR generation command to use SHA256 instead of SHA1, but I'm still not sure if this is the ...
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129 views

What is the impact of RSA key's size on CPU load?

I use ssh connection encrypted and compressed. If I use small RSA keys or very big RSA keys, what is impact on CPU load for compression, for decompression and on bandwidth (encrypted file size) ?
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599 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 ...
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119 views

Why is not safe to use the same public key in RSA?

In the RSA context, why is not safe to use the same n (public key)for different people?
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123 views

All users can write only one can read system

The system I want to implement has the following requirement: All users can insert some sensitive data, but only one, master user, can see it. There is any known, already implemented solution to this ...
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1answer
321 views

Shall I set “RSAAuthentication yes” in sshd_config if I use only ECDSA key?

In a context of proprietary client boxes and servers, I want to limit authentication to ECDSA keys. Historically, "RSAAuthentication yes" was used to enable authentication with RSA and maybe DSA keys. ...
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76 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 ...
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What are the odds of an RSA private key collision?

Given the various lengths of RSA key pairs (1024, 2048, 4096) what are the odds of two users having generated the exact same private key?
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264 views

Sharing RSA Public Key for decrypting JWT amongst Load Balanced servers

I'm trying to implement a cookie-less authentication mechanism for a web API that is stateless on the server (does not store session tokens) and can be load balanced across several servers. I have ...
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79 views

Problem with common factor in RSA [duplicate]

In the RSA key generation steps, what if two entities select a common factor to generate n (i.e. p*q1=n1 and p*q2=n2) resulting in gcd(n1,n2) <> 1 ? This will lead to a problem that everyone ...
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1answer
111 views

How to check a public RSA key file [closed]

Inside a shell script I want verify public RSA file. All I want to do is that find a way to check this file is a genuine public key file, nothing else. Can I ask experts here what are the ways I can ...