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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I need to transfer user's private key (RSA) to my App. Is file sharing a good solution?

I've asked a similar question here earlier iOS: Is it ok to store a RSA private key (use to decrypt text) in your application document directory? However, the person recommend me to use keychain ...
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When generating a 4096 bit RSA key pair, do both the private and the public key always have exactly 4096 bits?

When generating a 4096 bit RSA key pair, do both the private and the public key always have exactly 4096 bits, thus do not start with a 0 in binary representation?
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342 views

Sending Encrypted Messages with Hybrid RSA, AES and HMAC SHA-256

Is this a Secure strategy for sending a large Encrypted Message using Hybrid RSA 2048, AES 256 and authenticated with HMAC SHA-256: Given the Alice already has Bob's RSA Public Key, Alice: ...
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Using Different Algorithms in Single PKI

Assume the following Public Key Infrastructure: |Root CA (RSA) |-Sub CA (RSA) |-Sub CA (ECC) Is there any rational that explains why this would not be an acceptable implementation? Is the ...
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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 ...
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Why can I sign but not encrypt?

-edit- After following a chain of links from this question I see this is similar/duplicate of Why should one not use the same asymmetric key for encryption as they do for signing? but this question ...
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Is there a pre-established method for cracking RSA SecureID codes?

I am using the most modern version of RSA SecureID's tokens with a RSA server (used with a lot of governments and larger organizations ). I was just wondering if there was a pre-established method for ...
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232 views

What's RSA and ECC's role in TLS 1.2? [duplicate]

I'm trying to figure out what is RSA and ECC used for in TLS 1.2 cipher suites. Let's take TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 for example, communication between server and client would look ...
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758 views

How to prepare FATCA data transmission files with open source tools [closed]

Here is the context: to transmit FATCA data to US IRS service the IDES protocol defines the following steps sign the XML Payload.xml file with enveloping signature, SHA-256 with RSA private key, as ...
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99 views

Why FATCA IDES “protocol” does not use RSA encrytion directly on Zip archive ?

Here is the context: to transmit FATCA data to US IRS service the IDES protocol defines the following steps sign the XML Payload.xml file with enveloping signature, SHA-256 with RSA private key, as ...
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110 views

What's the signature structure in TLS server key exchange message?

I'm writing a TLS server. While handling ECDHE-RSA cipher suite, the server key exchange is needed. According to Elliptic Curve Cryptography (ECC) Cipher Suites for Transport Layer Security (TLS) ...
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Why is there a “des-ede3-cbc” in my rsa private key?

I have created an OpenSSL RSA private key and certificate request with 4096 bit with the following command: openssl req -newkey 4096 When I view the private key with openssl asn1parse -in privkey ...
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HPKP and multiple SSL certificates

Some weeks ago, we enabled the HTTP Public Key Pinning header on our website. As per the specification, we included not only the SHA-256 fingerprint of our current RSA key, but also that of a backup ...
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313 views

Good Library for RSA-2048 in C with some restrictions [closed]

I'm looking for a C/C++ implementation of RSA with a 2048 bit key (preferably read from a file). My target is an embedded platform, so it comes with some odd restrictions. The hardware restricts us ...
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14 views

Risk to pgp secret keys with known cleartext/ciphertext? [duplicate]

There are a couple of schemes which encrypt IMAP message stores to yourself using GPG/PGP. Which makes initial sense and would keep casual snoopers from getting email. But it raises a question as ...
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2answers
558 views

Chrome status warning on a netbanking secure site connection [duplicate]

I visited my bank's web banking site and clicked on the Green Lock in the address bar of my Google Chrome browser out of curiosity. Under the "Connections" tab Chrome spits out this disturbing ...
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610 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 ...
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59 views

Passing data among 3 parties with public key encryption

There are three parties involved in a repeated data transfer process: Client C, Broker B and Provider P. There might be multiple clients C. Broker B manages P's customer database. Each customer has a ...
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631 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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85 views

FREAK attack - why doesn't Finished message prevent it?

Here is my understanding of FREAK (let me know if I'm right please): 1) Client wants to use modern RSA in ClientHello 2) MITM forwards Export_RSA 3) Server says ok and sends an export RSA key, ...
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2answers
482 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 ...
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365 views

Encryption / Decryption algorithm generic across JRE (Sun/IBM)

Is there any encryption algorithm that is generic across all platforms? Is RSA generic across SUN/IBM JRE? Another question: will base64Encoder / base64Decoder sun.misc.BASE64Decode / ...
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858 views

How ECDHE is signed by RSA in ECDHE_RSA cipher

About ciphers that use ECDHE as Key Exchange and RSA as Authentication: How exactly this two algorithms work together, is ECDHE process encrypted by RSA public key? What are the DH parameters? ...
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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 ...
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Secret, Public, and Private Keys?

...and nonces. Can someone show an example of how this actually works using small intelligible numbers? For example: secret key: "100" public key: "10" private key: "1000" I am just trying to ...
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What is the role of RSA in ECDHE-RSA? [duplicate]

I have read some textbooks and not found a convincing explanation. In the cipher suite ECDHE-RSA-AES128-GCM-SHA256, what is the role of RSA in the first part (ECDHE-RSA)? This part of the cipher ...
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SSH Key: Ed25519 vs RSA

A lot of people recommend using Ed25519 instead of RSA keys for SSH. The introduction page of Ed25519 (http://ed25519.cr.yp.to/) says: [..] breaking it has similar difficulty to breaking [..] RSA ...
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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 ...
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145 views

Who uses 1024-bit RSA?

I know they're deprecated, but does anyone still use 1024 bit RSA encryption or certificates? Do you know of any examples of systems that use it today? What would be the implication if someone ...
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190 views

Managing keys generated with insufficient entropy

Since the Linux RNG which provides /dev/random (and by extension /dev/urandom) is seeded by "mouse and keyboard activity, disk I/O operations, and specific interrupts" (source, PDF) and since virtual ...
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185 views

Choose your own exponents in RSA?

In another interesting post, one of the developers/security researchers behind Phuctor suggests that using different exponents with RSA keys will "[increase] the costs of attacking your setup ...
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Offline RSA strong prime test similar to Phuctor?

One of the ways that RSA keys get consistently owned is when they're generated without enough entropy. Dan Kaminsky refers to a study which found that 1 in 200 RSA keys were badly generated and these ...
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Prevent padding oracle attack on key exchange process

I found in my searches that the padding oracle attack can be used against the RSA with PKCS1PAdding or OAEP padding, and I used this algorithm for a symmetric key exchange. How can I prevent a padding ...
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377 views

toy OpenPGP encryption with manually generated keys

I've been playing around with OpenPGP encryption for a little while. Here are the steps I've followed: Generate an unencrypted public/private key pair in my keyring with gpg --gen-key. Dump the ...
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311 views

RSA: same symbols in plaintext give same symbols ciphertext?

I just started studying Information Security, but I just ran this program: http://www.sanfoundry.com/cpp-program-implement-rsa-algorithm/ and faced this strange thing. For small keys (don't try to ...
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What is encryption by RSA with AES? [duplicate]

By visiting some websites, like bank websites, we can see for example: TLS_DHE_RSA_WITH_AES_128_CBS_SHA, 128 bits, TLS 1.0 I would like to know: What does mean CBC? TLS 1.0 is an old version, is ...
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Secure Hash of a very short payload - is it possible?

I am looking to verify the integrity of a very small payload, approx 64 bytes, which will be stored in a QR code. I need to verify that the payload has not been generated or altered by an attacker. ...
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700 views

Determine private key size using public certificate [duplicate]

I have a public certificate in a PEM (.pem) file -----BEGIN CERTIFICATE----- MIICsjCCAZqgAwIBAgIJAMA1YIQ2JLXDMA0GCSqGSIb3DQEBBQUAMBExDzANBgNV ... 29V/R9RZOoSBHDzGPL84wm4qojMuwQ== ...
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How many qubits are needed to factor 2048-bit RSA keys on a quantum computer?

I've been reading about quantum computing and turns out that 512-bit quantum processors are already a thing. I also read about Shor's algorithm, which can break RSA and several asymmetric encryption ...
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174 views

RSA vs DSA Digital Signature Message Digest Recovery

I'm learning about signatures using RSA and DSA, I've come across this little fact: RSA can recover the message digest from the signature, whereas in DSA this isn’t possible – you have to have the ...
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1answer
145 views

someone may be doing something nasty

I have an ssh server. earlier toady, I was about to login to my server, when I got a message that said something along the lines of "Someone may be trying to do something nasty" and indicating a man ...
2
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1answer
213 views

How does this encrypted webmails works?

In the last days I was looking on Tutanota, ProtonMail, LavaBoom, and others webmails that promise to respect users privacy. For all those, the one I most liked was Tutanota. I did few tests with ...
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If TLS 1.2 is considered unbreakable, why do the NSA and other agencies invest in supercomputers? [closed]

If a 2048-bit RSA key and a 256-bit AES key are considered to be unbreakable within the foreseeable future by any kind of computer, why do the NSA and other intelligence agencies invest in ...
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198 views

How to use IIS ssl certificate(CNG) for data encryption

I want to use RSA to encrypt/decrypt some data using IIS's ssl ceritifcate, from within a web service(WCF). I've managed so far to do this by using .NET security ...
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140 views

RSA private/public keys

Is it possible to recover a private key, given a public key and a substring/a part of the corresponding private key?
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259 views

RSA vs DSA working methodolgy?

I have looked for various answers but I am being confused on how does RSA can be used for both Digital Signatures and Encryption/Decryption like in "TLS_DHE_RSA_..." or "TLS_RSA_.." cipher suite ...
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RSA key sizes v/s public key sizes

I am new to cryptography. I have an api provided by a bank. The banks says that they are using RSA algorithm with 2048 bits. We used this api first to get the public key. Here is the sample public ...
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Looking for a (simple) utility to decrypt rsa-encrypted text in Windows?

Quick question: I'm looking for a simple utility program to be able to decrypt rsa-encrypted data (either base64-encoded or binary attachment) on a Windows workstation. Scenario: There is a group of ...
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484 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 ...
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626 views

Asymmetric / end to end encryption for web messaging app

Background I'm trying to design a secure and sustainable web app for messaging. The purpose is to learn how to create secure web application. The application is suppose to be written in Javascript ...