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 does signing work with Elliptic Curve Crypto?

So I have read up and have a decent understanding of how the crypto works with Elliptic Curve Cryptography. I also think I have an understanding of how signing works with things like Elliptic Curve ...
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Isn't this the same as using a certification authority?

Taken from Wikipedia, here is the pretext to my question: A certificate authority (CA) is an organization that stores public keys and their owners and every party in a communication trusts this ...
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RSA, SSLStream - KeyExchange

I'm using sslstream to communicate a client and a server, and i need to use RSA encryption, i have made some tests with a brute keyexchange, using sslStream.write(modulusPublicKey). And receiving like ...
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108 views

Is a android app signing certificate unique?

The Certificates that are used to sign Android applications are generated by the user and not checked or signed by any authority. They are RSA or DSA Certificates and as i read on ...
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3answers
127 views

Generating deterministic X.509 certificates?

Is there a way to deterministically create an RSA private-key for an X.509 certificate, ideally through a library which has been vetted already? i.e. user enters some phrase like "this is my private ...
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2answers
97 views

Why RSA signatures based on the hash of the message? [closed]

Why RSA signatures based on the hash of the message rather than the message itself?
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172 views

RSA Signing Key Rotation

I understand the details of RSA encryption/decryption in that a public key can be distributed in the clear since all it can really do anyway is encrypt data. I also understand that this public key can ...
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2answers
206 views

Expiring AES Key

Is there any way to make an "expiring" AES key? Here's scenario to give a better picture: Say Bob has some data which he would like to share with Alice. Alice has a public and private key, let's say ...
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1answer
239 views

Encrypting a symmetric key or Small File using TPM and Windows (TBS?)

I'm looking at encrypting a small (500bytes) file using the TPM. This is either doing assymetric encryption with the TPM directly, or using the TPM to store a symmetric key for decryption. This needs ...
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155 views

RSA verification time

For a any processor of these or any other processor armeabi (v7-A, Cortex A8); 2012 TI Sitara XAM3359AZCZ100; 1 x 1000MHz armeabi (v7-A, Cortex A9); 2012 VIA WonderMedia 8850; 1 x 1200MHz amd64; ...
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1answer
472 views

When SSL detect a replay attack?

Suppose an attacker records all messages of a SSL handshake (RSA one-way), and starts a replay attack. When (after which message) can the server possibly detect the attack? Now suppose the attacker ...
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2answers
186 views

RSA-Based Signature Algorithms

From Beginning Cryptography with Java - chapter 4, digital signatures: Signatures are created using the RSA algorithm by applying the RSA algorithm using the private key and then distributing ...
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265 views

Why is it difficult to break RSA?

Given that an attacker only knows the public key and cipher text, why is it difficult to decrpyt the message ? If the knows the N value will he be able to decrypt it ?
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Recommended operational security for generating one's primary key pair?

I have been looking for an operational security guide for generating one's asymmetric key pair for (Open)PGP. I have found plenty of technical guides for how to use GnuPG to generate RSA key-pairs, ...
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1answer
81 views

Private and public key need to have same algorithm?

The private and the public key from the cert must have the same algorithm, correct? EDIT: Yes of course pub / priv are a key pair. So this code would be legal, to be more flexible (e.g. ECDSA or DSA): ...
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2answers
106 views

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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1answer
499 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 ...
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1answer
474 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. ...
3
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1answer
215 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
1k 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
494 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
557 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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2answers
1k views

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
198 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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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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997 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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149 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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36 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
456 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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160 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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122 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
109 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
283 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
120 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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190 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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170 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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313 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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339 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
3k 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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210 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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242 views

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
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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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604 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
1k 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
124 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
296 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
61 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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584 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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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, ...