Encryption is the process of transforming plaintext using a cipher to make it unreadable to anyone except those possessing the key.

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ECDSA ciphers and forward secrecy question about key exchange

I have heard that with forward secrecy that the ECDSA ciphers generate different keys for "each session" because they are not dependent on the private key of the server. My question is how is "each ...
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CryptoWall 3 - how to prevent and how to decrypt?

My father's computer is now infected with CryptoWall 3, according to the link below. http://www.bleepingcomputer.com/virus-removal/cryptowall-ransomware-information#CryptoWall Is there a way to ...
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Is applying AES multiple times safer?

The KeePass security help page talks about preventing dictionary attacks To generate the final 256-bit key that is used for the block cipher, KeePass first hashes the user's password using ...
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What are private key cryptography and public key cryptography, and where are they useful?

I don't understand the real world usage scenarios of these cryptography methods. Can any one please explain how they work, with examples and also their usage in the real world?
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Cascading Encryption Algorithm using mcrypt or GnuGP

I'm trying to a cascading cipher encryption algorithm to encrypt a textfile via mcrypt. I'm essentially trying to emulate the behavior of TrueCrypt, where it can cascade two or three different cipher ...
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What is the difference between https://google.com and https://encrypted.google.com?

Is it there any difference between the encrypted Google search (at https://encrypted.google.com) and the ordinary HTTPS Google search (at https://google.com)? In terms of security what were the ...
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2answers
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stronger encryption for SSH keys

I configured my server to encrypt user passwords using 500,000 rounds of SHA-512. The question is, how does the standard AES-128-CBC encrypted SSH private key stack up to that, provided the same (or ...
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3answers
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Why can a Tor exit node decrypt data, but not the entry node?

Me -> Node A -> Node B -> Node C -> destination The documentation on Tor always states that only the exit node C can see plain text data. How is this possible without me talking to Node C ...
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4answers
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Standards for encrypting passwords in configuration files?

My workplace has a standard that plaintext passwords are not allowed in application configuration files. This makes enough sense on its face, in case someone gets access to the config files they ...
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Which Instant Messaging services use or allow secure protocols, and what do those protocols cover?

We all know there's a myriad of Instant Messaging (IM) services out there. But, which of these services uses or permits protocols that actually secure your communications? For those that do, what ...
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Can my IT department read my Google Hangouts chats while at work?

Is Google hangouts encrypted? Would my work's IT guys be able see pictures and text I send while on a work computer? Yes I know I shouldn't be sending stuff I don't want them to see while at work, but ...
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5answers
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Securing a laptop against attacks (article)

I came across this article when looking for ways of hardening my laptop, and this guide seemed extremely thorough. It is perhaps overly paranoid, but it will be good to have a guide I can trust should ...
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In PGP, why not just encrypt message with recipient's public key? Why the meta-encryption?

It's described very well by this diagram. It seems like the process used is convoluted and more round-about than it needs to be. Why is an intermediate random key generated for the payload's ...
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How does non-ephemeral Diffie-Hellman key exchange become compromised in SSL when the RSA private key is leaked?

From my understanding, one of the major reasons we recommend Diffie-Hellman Ephemeral (e.g. DHE or ECDHE) over non-ephemeral DH, for SSL / TLS, is that compromise of the RSA private key (i.e. private ...
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2answers
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Timing attack against HMAC in authenticated encryption?

In an answer to another question of mine, it was noted that a class using standard string comparison functions when checking the HMAC in authenticated encryption would make the class vulnerable to ...
43
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9answers
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Are powerline ethernet adapters inherently secure?

I have 2 Zyxel PLA407 powerline adapters. Router is downstairs connected to one adapter, other adapter is upstairs about 30 feet away connected to a desktop. I have a house, not an apartment or ...
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1answer
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When using AES and CBC, is it necessary to keep the IV secret?

If I encrypt some data with a randomly generated Key and Initialization Vector, then store all three pieces of information in the same table row; is it necessary to encrypt the IV as well as the Key? ...
12
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3answers
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Using TPM with DMcrypt?

Is it possible to use TPM for storage of some private key? It's not a full-disk encryption , I want it to be compatible with existing LUKS, just add another key, and store it in the TPM.
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2answers
850 views

In a browser web server communication, who decides which encryption protocol to use [duplicate]

My IE browser has SSLv3.0, TLS 1.0,1.1 and 1.2 enabled in the advanced settings. And (I was informed by my server admin) my web server can encrypt data in SSLv3.0 and TLS 1.0 Now which system ...
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6answers
2k views

How can the impact of cold boot attacks be minimized?

Short of powering down and maintaining physical security for sufficient time, what are effective strategies for keeping keys from being disclosed by cold-boot attacks, and can anything be done without ...
15
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5answers
1k views

How should passwords be stored if they must be recoverable?

By "encrypting" passwords you are violating CWE-257: Storing Passwords in a Recoverable Format. But this is exactly what the French government wants. They want to be able to obtain the passwords of ...
11
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5answers
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Can Skype chat be protected from snooping? Are there safe alternatives?

I use Skype a lot. With all of my clients, staff, contractors and friends, however, the acquisition by Microsoft worries me, as two of my clients are direct MS competitors, and I often work on long ...
8
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3answers
288 views

Securing an E-commerce site

I'm building a custom e-commerce site, and the user will input their credit card details on the site instead of being directed to the payment gateway's site. I'm confused as to what the critical ...
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1answer
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Will double encryption increase the security of cipher vs bruteforce?

Assume I have a function encrypt(mes,key) where mes is the message, and key is the key. The length of key is 64 bits. Last but not least: assume the only way to crack my cipher is a brute-force ...
17
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3answers
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Can a nation-state adversary perform a MITM attack by compelling a CA to issue them with fake certs?

As I understand it, with any encryption system based on a trust chain / CAs (eg SSL, TLS, S/MIME), it would be possible for a nation-state adversary (such as the NSA) to compel the CA to issue them ...
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Encryption and the “security time decay” of prior encrypted data

This question is on the assumption that any data once encrypted, may (eventually) be decrypted through Brute force (compute power/time) Exploits in the cryptography used Theft of private keys ...
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4answers
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Doubling up or cycling encryption algorithms

I've occasionally read the suggestion to enhance security by either doubling up on encryption algorithms (encrypt a message once with one algorithm, then encrypt the ciphertext again with a different ...
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2answers
2k views

How would I implement “Broadcast Encryption”?

I have a stream that I want to encrypt for broadcast to 10,000 subscribers. I know I should encrypt this data using a symmetric key; and also intend that this symmetric key will be rotated every 30 ...
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3answers
1k views

How secure is aSSL (javascript)? Does it effectively mimic SSL?

Some of you may be familiar with the aSSL project, which uses AJAX/PHP to mimic the SSL protocol. It uses RSA 512 or 1024 for the keys, and AES for the actual data. It looks impressive to me in ...
13
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6answers
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Where does SSL encryption take place?

I checked the data transmission of an HTTPS website (gmail.com) using Firebug. But I can't see any encryption to my submitted data (username and password). Where does SSL encryption take place?
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5answers
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How can one secure a password/key in source code [duplicate]

If there is a need for source code to have a password in it, how should this be secured? This is purely an example, but say there is an app that is using an API, and you don't want to expose ...
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3answers
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Encrypting user data using password and forgot my password

I am planning to do a web application which stores a lot of personal stuff (info, photos...). And to give users a sense of protection, I want to encrypt the data before storing it to the database. ...
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3answers
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When is it appropriate to SSL Encrypt Database connections?

Let's say I have a web server I setup, and then a database server. However, they are communicating locally and are behind firewall. In my opinion, no SSL is needed here right? The only time to use ...
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1answer
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Is hardware based disk encryption more secure that software based?

As a spin-off of my question on "Advice on buying an encrypted disk" -- and in an effort to address the question "how is hardware based disk encryption better?" -- I've started a new question. My ...
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3answers
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Are the encryptions “broken” with great computing power?

http://www.dwavesys.com/en/pressreleases.html#lm_2011 Lockheed Martin Corporation (NYSE: LMT) has entered into an agreement to purchase a quantum computing system from D-Wave Systems Inc. I'm ...
13
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3answers
538 views

Can I use the same password both for SRP and for client-side encryption?

Suppose a less-than-trusted server is used to store users' confidential data (encrypted at the client side), and both tasks - authentication and encryption/decryption - should be doable with a single ...
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2answers
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How might the U.K. Government's proposed internet surveillance equipment “bypass” encryption?

http://www.channel4.com/news/black-boxes-to-monitor-all-internet-and-phone-data http://rt.com/news/uk-privacy-internet-freedom-186/ 'Black boxes' will be installed by internet services providers ...
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4answers
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How effective is iPhone 3GS and 4 device-at-rest encryption?

My primary goal is to protect Activesync-based communication from being copied or stolen from an offline device. In that context how effective is iPhone 3GS and 4 encryption?
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1answer
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Security of bcrypt/sha256 key used with AES to encrypt a file

I'm looking to encrypt files using secure hashing and encryption algorithms in Python. Having used bcrypt in the past, I decided to use it for my passphrase calculator, then pass the output through ...
4
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1answer
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Are there any holes in this security design?

This design is for transport security between a client and a server. I'm planning on using it for a cloud storage system. I would like it to be secure against you-know-who. I'm trying to prevent the ...
5
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6answers
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Mysql - two-way encryption of sensitive data (email addresses) outside of Apache, PHP and MySQL

We store user email addresses in our database, like many other websites. While we do take pride in the security measures in place, sometimes "just enough" is just not enough. We've begun looking into ...
3
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1answer
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Using GPG or PGP for symmetric database encryption/decryption in c#

I am looking to symmetrically encrypt/decrypt information in a database. This info consists of short pieces of information, which need to be individually encrypted when a specific method is called. I ...
2
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4answers
816 views

For someone who has a key and ciphertext, is it possible to find out what encryption algorithm was used?

I am new in cryptography, and while learning a different questions pop up in my mind. Here is one of them. For someone who has a key and ciphertext, is it possible to find out what encryption ...
2
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2answers
898 views

Determine encoding/hashing methods used based on knowing the input and output only?

If I know the initial value of a string and the resulting hash but have no access to the system that produces the output, how can I determine what has actually occurred so I can reproduce the hashing ...
2
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3answers
356 views

Without SSL, what vantage point does one need to MITM non-SSL'd HTTP?

OK, so there are two things here: being able to read the content of the requests and responses, and then being able to modify them. The former may depend on the latter, I'm not sure. But basically, ...
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How to tell what encryption is being used [closed]

How do you tell encryption algorithm used by reading its output? Here is the one I am trying to figure out Åbd$ý ...
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17answers
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Can we still provide confidentiality when cryptography is outlawed?

In certain jurisdictions, use of cryptography by the private sector is limited: e.g. there are reports that in the UAE and other countries not all of the encryption capabilities of the BlackBerry are ...
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1answer
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iOS Encryption Details

Following on from this question Does anyone have any details/resources on the technical specifics of how apple implement encryption on their iOS 4.x series devices? The Apple marketing material here, ...
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9answers
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Is full disk encryption on a server in a secure data center pointless?

I am having a debate with several people regarding how much protection full disk encryption provides. dm-crypt is being used to encrypt data which is required by my company to be encrypted at rest. ...
31
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5answers
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Why AES is not used for secure hashing, instead of SHA-x?

As far as I understand, AES is believed to be extremely secure. (I have read somewhere that it would certainly not be broken in the next 20 years, but I am still not sure if the author was serious.) ...