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You are correct, however note that there is no indication that AES256 is cracked (and normally it won't be anytime soon either). Considering the strength of AES256 it will take several millions of years (even with quantum computer as the best known theoretical attack is Grover's quantum search algorithm. This allows us to search an unsorted database of n ...


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To me, the main reasons are related to key management, rather than cryptographic security per se. For asymmetric crypto, especially the period during which you want a public key to be valid may strongly depend on the intended use of that key. For example, consider a system in which a component must authenticate itself towards other components. Next to ...


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Sorry, but I see it too complex with little benefit. Your algorithm requires the user to "remember" r, which is a random value. Given that prerequisite (the user will somehow remember r in a secure way), he could as well be remembering the password itself.¹ An outside attacker would need to compromise the user's laptop and either our server or the ...


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My preferred method is SSHFS. Your NAS server runs a SSH server which you then connect to from your remote machine. Leveraging SSHFS it will mount a drive on your remote machine via SSH (secure, encrypted) from the server you specify. I've not used the windows client version so YMMV. ...


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telegram probably will use features that are built in a mobile phone operating system to keep those cryptographic keys, for example Android key Store or Apple's Keychain. these key store mechanism will in turn utilising the hardware provided by mobile phone to prevent key extraction.


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I'd like to to rephrase your question as this: "Is there a way to make sure, in a cryptographic way, that two different views of some data are, in effect, related the same information ?" I would see two approaches to that problem. The first one starts with the data, the second one, with the final view. Data-centric In order to implement this, you need to ...


1

I think you need to separate in your mind confidentiality protection from authentication. It is quite possible to simultaneous generate a key between two parties over the Internet, with everyone from your ISP to every Govt possible listening in, yet they cannot as an eavesdropper also generate that key. That is the essential point of say the ...


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Yes, but you need some way to be sure that a public key of the recipient corresponds to the person you want to talk to. When you rely on a central service to find a public key for a name/email address/phone number, you're vulnerable to MITM by the "directory service". To get a public key for a person using the internet you can use PKI (and then you're ...


2

I think there is an additional problem/challenge with your scheme: Beside the problem of having the key pairs generated by the server, this scheme also allows for a man in the middle attack: A asks for the key of B, server answers with his own key C. Now the server can decrypt, read and encrypt again for B and send the new ciphertext to B. Neither A nor B ...


1

This was quite a good question and despite some comments, is very relevant to security. It is also a real problem. Don't get caught up in the mirky details. instead focus on the general problem, which could be equally applied to real world issues faced by Journalists or pretty much anyone who lives in a country where government control and civil liberties ...


1

In my opinion, to password protected zip file is more safe than not to do that. This article explains how to make an encrypted (password protect) compressed file (referred to as 'an archive' file).Note: The compression program built-in to (included with) the Microsoft Windows operating system since the release of Windows XP cannot password protect a ...


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Possible solution would be to use rule-based filtering/re-directing on the server and address-spoofing. 1.) Mail from Alice's account to Bob@Bob.Bob is immediately server-re-routed to a clandestine mail account which he uses for his affair. Unless Eve is able to view server filtering rules and/or the logs on the mailserver she will never know that Bob is ...


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Very strange that noone mentions the solution how General David Petraeus hid his love affair from prying eyes: Both have a shared email web account. Each one is saving his/her message to the other person as Draft without sending them at all. So the only detectable transmission (which is normally encrypted) is between Petraeus and the server (Yahoo, Google ...


2

TL;DR Yes, if done properly, the system you've designed should provide a small security gain, but it probably isn't the best option. The expanded version: When we design security into a system, we first develop a threat model, and then we figure out how our system is going to mitigate those specific threats. So, the question for you is: "What is the ...


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If Bob can own Alice's computer (all of them) without being detected, he can wrap a bot around her email client which collaborates with Bob in the way most convenient to him, but then presents the communication to Alice as coming in plaintext from Bob's address, even though that's not the truth. Outgoing emails to Bob are also intercepted and communicated ...


2

These days basic Software Defined Radio (SDR) kit has become very affordable so you can now obtain the RTL-SDR USB stick for about $15 and perform some GSM sniffing on a standard laptop running Wireshark. The GSM capture is done using the RTL-SDR and the airprobe tool (which builds on GnuRadio) that relays the packets to Wireshark, via the GSMTAP port (UDP ...


3

You are presuming that a person can have only one personal email address, but that is not true. If Alice is not a knowing participant in Bob's adultery, there should be no reason for her to need to know that bob@bob.bob is the 'only' personal address for Bob. He could give her bob@gmail.com and she would be none the wiser. Alternately, if Eve is only ...


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An offline/local encryption/hashing server. Imagine this an user register himself >on the website but instead of the current site hashing and storing the password. This exposes the password to a unknown server, with unknown security for the password itself. Its better to NEVER send an password over the wire at all. you could use a java script hashing ...


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Let's break this up: Bob and Alice want to engage in two-way email communication. Bob and Alice need to use their personal email addresses. Eve has the ability to observe all communication in the system. Eve must not learn about any special communication between Bob and Alice. (Alice must not learn that Bob is married.) The last statement (5) prevents ...


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No solution. As Philipp points out, your requirements boil down to "Bob and Alice can only communicate in plain text directly over a monitored channel", because if Bob uses anything else Alice will realise he is hiding something.


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Bitmessage may be the solution. See https://bitmessage.org/wiki/Main_Page. Bitmessage hides who is communicating with whom, and all messages sent through the network are encrypted, authenticated, and digitally signed. From Wikipedia: Bitmessage is a decentralized, encrypted, peer-to-peer, trustless communications protocol that can be used by one person to ...


3

The modern way of sending e-mails already gives an answer to Bob's problem. In fact, a service like GMail already encrypts the communication of e-mails between two GMail's addresses. Furthermore, Bob can connect to his e-mail front-end using HTTPS rendering all eavesdropping void. If we consider that Bob's is careless and sending his e-mail to his new ...


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Let me make sure I understand. Your user will run a local application that is capable of decrypting your encrypted file and of storing it (or parts of it) in memory in a readable format. Your adversary is the user; the user is assumed to want to hijack those permissions stored in the encrypted file. I also assume the user is root on that machine so she can ...


1

There might be a bit of confusion here between "RSA Laboratories", the organization that edits the PKCS standards, and RSA, the cryptographic algorithm. PKCS#1 is one of the PKCS standards, thus edited by RSA Laboratories; it talks about the algorithm RSA, and only about the RSA algorithm. In particular, there is no such thing as a "PKCS#1 format" for ...


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Can EC keys be converted to RSA PKCS#1 keys? And if yes, how? No. RSA has nothing to do with ECC. Now for some crypto there is both a regular version and an EC version. (Examples are: DH/ECDH, DSA/ECDSA.) But: There is simply no such thing as "ECRSA". There is only RSA.


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The "constantly regenerating pepper" component feels like too much complexity for the relatively niche attack scenario it protects against. It seems to me that the moving parts required to support it are more likely to introduce an attack vector (or a scenario for unrecoverable data loss) than protect against one.


1

In most cases, what seems like the best way to handle this is to use the functionality provided by your OS to store credentials and password. On OSX and iOS, you can use keychain. Under Windows, you can use the credential manager (also called password vault), DPAPI or the certificate store, depending on what exactly you want to do. In any case, I suggest ...


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GnuPG is applying compression before encryption for reasons of efficiency (compression is cheaper than encryption) and security (compression might prevent some attacks introduced by flaws in the OpenPGP design). As you're encrypting a series of nothing, this can be compressed very well. Consider using /dev/urandom instead. You can disable compression using ...


1

The POODLE attack is actually very hard to pull off in real world conditions. A SecurityMetric blog post lays it out well: Here’s an explanation of how an attack would have to take place in order for an attacker to exploit POODLE and assume the user’s identity on the target site. The victim must be logged into a site using HTTPS (and the session ...


2

the first security hole is your shared "el-cheapo" server. if you can not trust your machine, you can not trust your applications. what this means is that if you have no controle over the machine itself, adding security to it is pointless, an attacker will just attack your webserver instead of your connection and makes sure he can do anything he/she wants ...


1

If you read their privacy statement it more or less says you give them full access to your bank account and the rights to your full banking transaction history if you use the service. Personally I find this unacceptable. Further more it is totally unnecessary for them to access your account and to process a payment. What I have done in the past is simply ...


2

Before we start, I think it's important to point out that the round count is stored in the KeePass dictionary file header, so that KeePass itself can open your password files regardless of the setting in its preferences. Otherwise you wouldn't be able to open a KeePass file on another machine if it had a different number of iterations, without first ...


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You're assuming incorrectly: the number of iteration is part of the "public" headers of the keepass file format. Its necessary otherwise Keepass itself wouldn't know how many iteration to perform (it would have to perform the all). You can verify that this by checking the the keepass source code. That doesn't mean increasing the amount of iteration used by ...


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First off, there are ways to mount encrypted partitions without having to enter the passphrase manually or storing it on the system that is being protected. Look at Mandos for one example of this; it's basically a client/server application that stores the key to unlock the encrypted container separate from the container itself. An attacker would at the very ...


0

Can't deduce much from your question but if you are responsible for code repository structure then I'd recommend you differentiate config repository and code repository. Where Code repository would have the actual code & config repository would held these secret keys. If I were you, I'd also ensure these secret keys are not stored in plain text and ...


4

Yes, assuming there is no randomness added to the message during encryption (or that Bob reveals that randomness) then anyone who encrypts the plain-text message with Bob's public key will get the same cipher-text that Bob received / published. That is, of course, assuming that Bob can prove the cipher-text is genuine.


1

"I can't find any documentation on how key derivation works. There are some mentions of PBKDF2, but that's about it. " DiskCryptor is very visibly derivated from Truecrypt and shares some of its old style constants. It uses SHA-512 with 1000 iterations as key derivation algorithm according to ...


0

1-time pad remains the strongest, uncrackable (if used properly) encryption. Of course, you DO have to swap pad face to face, but I reckon 95% of people who require this level of security WILL meet before setting up secure communications. Just specifying which 256-bit key to use for a particular message works perfectly and is used by the security services.


1

Google has an exploit called RowHammer which allows a user to read the contents of RAM that is adjacent to the data being written to. Encrypting the RAM would make this exploit much more difficult. “Rowhammer” is a problem with some recent DRAM devices in which repeatedly accessing a row of memory can cause bit flips in adjacent rows. We tested a ...


2

This is normal. It's how EFS works. Although it is common to refer to file folders with the encryption attribute set as “encrypted,” the folder itself is not encrypted. When encryption is set for a folder, EFS automatically encrypts all new files created in the folder and all files copied or moved into the folder by using My Computer. (Source: ...


2

Passports does not encrypt data, instead it uses Basic Access Control, as a authentication layer, to prevent access to passport data without authorization. The authentication data required to access the passport is written in the MRZ, so ideally, you would need to optically read the passport to get the "password" to open the RFID chip. However, passport ...


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1: The advantage of S/MIME over PGP is that you sign/encrypt a complete mime entity, not a text. This makes it possible to sign/encrypt a entire message/rfc822. Yes, headers must be visible and changeable to the MTA, but that can be accomplished by taking the WHOLE mail, S/MIME sign or encrypt it, and then package the signed/encrypted S/MIME entity it in a ...


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Every time you browse GMail or your bank's website using HTTPS from your laptop in a coffee shop or airport, your are broadcasting all sorts of ciphertexts to everyone who cares to listen in. It had better be safe publicly to share ciphertexts. Assuming a great many things about the strengths of the chosen ciphersuite, crypto implementations, and ...


2

Yes, sharing the ciphertext is safe. Kerckhoffs' principle, which modern cryptosystems are designed around, states that the system should be secure if everything about it is known except the specific key used for encryption/decryption. Additionally, security through obscurity is rarely effective. What you're (somewhat) getting at in your question is that of ...


2

WPS would generally only be used for the initial connection because the wireless network settings (pass-phrase/SSID) are saved on the connecting device. I don't know if it is possible to "force" clients to connect every time with WPS. If it is...I would not recommend it. WPS is insecure. A quick search for "WPS Hack" on a search engine will provide you with ...


0

Seems that what I'm hoping for doesn't exist. I'd love to see something like this in PHP core because most people just don't have the time, interest or inclination to learn things like this but will still inevitably need it. I ended up using a library. https://github.com/defuse/php-encryption looked very good, but not available on Packagist, so I went with ...


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Exposure of ciphertext does not inherently decrease is security of the algorithm. However, if the ciphertext is more easily accessible it is more likely to be found by an adversary. If your adversary has means to steal your private/shared keys, rubber hose you, etc its more risky to increase exposure. You may always want to consider that in the future a ...


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That is exactly what encryption is designed to safely enable. If Bob and Alice could safely share the message without allowing attackers and eavesdroppers access to it, they would not, in fact, need encryption at all. So, yes, it is safe to allow any and everyone access to the ciphertext. You do want to authenticate it so that it cannot be tampered with ...


2

Generating rainbow tables is never the best way to attack a single instance. Rainbow tables are precomputed tables: you do a lot of computations in advance, under the hope that you will be able to apply these computations to several attack instances. Precomputed tables (rainbow or not rainbow, this does not change anything here) all follow the same pattern: ...


1

I use Prot-On, it is free app that allows decide who and when can access documents on Google Drive and track their usage at any time. For the moment, it is the best. http://www.prot-on.com



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