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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Block chaining modes to avoid

Everyone knows that ECB operation mode with a block cipher should be avoided because of clear and obvious weaknesses. But little attention is given to comparison of the other modes in the context of ...
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How would you store a 4 digit pin code securely in the database?

I'm familiar with password hashing, using salts, bcrypt etc. But it doesn't seem like this would work to store a 4 digit pin code since the attacker could try all 10,000 combinations quite quickly. ...
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How to secure a WiFi network?

What do I have to do to secure a WiFi network? Is there any best practices? I have been recommended to use WPA2 encryption on the router, is that enough? What can I do to improve the security even ...
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Secure Configuration of Ciphers/MACs/Kex available in SSH

Following on the heels of the previously posted question here, Taxonomy of Ciphers/MACs/Kex available in SSH?, I need some help to obtain the following design goals: Disable any 96-bit HMAC ...
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What are best practices to adhering to HIPAA encryption requirements?

As HIPAA's language is somewhat vague when it comes to actual technical requirements, what are best practices for PHI encryption for HIPAA compliance? I've seen varying levels at different ...
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Is “real salt” the same as “initialization vectors”?

In the question about real vs. fake salt, the answers describe how real salt 'perturbs the encryption algorithm.' I know roughly how initialization vectors work; is this the same concept, or something ...
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How does Firefox encrypt passwords without selecting Master Password?

I know that the file logins.json contains all my encrypted passwords in Firefox browser. How does Firefox encrypt these passwords if I don't use the 'Master Password' option? Does this mean key3.db ...
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Multi-boot with full hard drive encryption and pre-boot authentication

How would I set up a multiboot system which supports full hard drive encryption and pre-boot authentication. I have a system with Ubuntu, Windows 7, Windows XP, and I would like to install Red Hat. ...
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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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Is it possible to “read” secure (using SSL or TLS) messages if you know the message?

If I am communicating over a secure line (secured using SSL or TLS) and I send the server a message. Could someone eavesdropping tell what that message was if they knew before hand a list of messages ...
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Why does an encrypted message sometimes end in “==”

As a programming exercise I need to decrypt a message. The only clues that I have is that it seems are: The encoded message contains only Base64 Characters a n letter sequence (n in 1,4,7,10) times ...
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Is SHA1 weak for SSL?

I noticed that today after I scanned a site on the Qualys SSL Labs site that SSL ciphersuites which use SHA1 are now highlighted as being "Weak". It seems this has just happened; I scan sites pretty ...
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Does holding an AES-encrypted string and its cleartext from a database help an attacker in decrypting other parts of the database

I have a question regarding Encryption. Say an attacker stole my entire database. In that database all the data was encrypted. If the attacker took one piece of encrypted data and for some reason knew ...
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Strength of WEP, WPA and WPA 2 PSK

I know there are three method for wifi security. What are the relative strengths of the password encryption in WEP, WPA and WPA2 PSK?
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Why is Amazon's home page not encrypted? [closed]

I've been working on my very first web application and I usually refer to Amazon.com as my role model. I'm very interested in deploying my web application with SSL/TLS. However, there is one thing ...
21
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1answer
917 views

Linux, TRESOR and XTS

I want to switch from using LUKS for full disk encryption to TRESOR. TRESOR tries to prevent cold boot attacks by storing the encryption key in the CPU's registers. It uses the kernel's crypto API for ...
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When encrypting cloud-stored data, is it acceptable to use the user's account password?

I'm developing a web service that stores sensitive personal information (such as telephone numbers, addresses, full names, and email addresses) in a database, such that it can be accessed from ...
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Why is security through obscurity not a good option for encryption? [duplicate]

I feel like there must be a simple explanation, but I've been looking around haven't found any wholesome answers. Take for example my name is Alice and my best friend Bob and we want to communicate ...
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Why should one not use SSL? [duplicate]

I see a lot of posts all over the web asking whether or not they should be using SSL to secure their website, or if it's really necessary to do so when the content of their site does not contain or ...
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TLS Bicycle Attack - What cipher is free from flaws to use?

Recently a novel attack on TLS stream ciphers was developed by Guido Vranken, dubbed Bicycle and referenced in this Websense's blog post. It was based on a characteristic of stream ciphers that says ...
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What's the advantage of using PBKDF2 vs SHA256 to generate an AES encryption key from a passphrase?

I'm looking at two comprable pieces of software which need to encrypt data on disk using a passphrase. One uses PBKDF2 to generate the encryption key from a passphrase, while the other uses two rounds ...
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What are the good use cases for disk encryption?

I've been researching disk/file system encryption, and on the surface it seems like a good idea for a lot of things. But as I dig further, the security it offers seems more mirage like than real. ...
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Backing up sensitive data - pitfalls and best practices

Obviously, securely backing up sensitive data is a challenge. A remote backup is important for surviving a variety of disasters. What are some of the "gotcha's" lurking out there, and what best ...
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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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IPsec (Internet Protocol Security) facts

Internet Protocol Security (IPsec) is a successor of the ISO standard Network Layer Security Protocol (NLSP). What are the advantages, disadvantages, other interesting facts regarding the protocol?
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GPG File size with multiple recipients?

If I encrypt a file for multiple users how does the file size change? Does the size of the output double for two users. How about 10 or 100 users?
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How does a crypter for bypassing antivirus detection work?

I am talking about crypters used to encrypt files like viruses and keyloggers for the sole purpose of bypassing antivirus detection. How do they work?
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Compute the AES-encryption key given the plaintext and its ciphertext?

I'm tasked with creating database tables in Oracle which contain encrypted strings (i.e., the columns are RAW). The strings are encrypted by the application (using AES, 128-bit key) and stored in ...
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What are the differences between MD5, SHA and RSA?

MD5 tools output hexadecimal values. In the same manner, do SHA and RSA together produce a hexadecimal (or any other) output? What are the differences between the MD5, SHA and RSA algorithms?
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Is it alright to tell everyone your encryption information?

I have an account in an online banking system and they have the FAQ with something like this: How secure is the <Online Banking System Name>? Each page you view and any information ...
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Is “Why Should You Avoid AES In MySQL?” true?

From a 2012 Smashing Magazine article quite a bold statement is made to avoid AES in MySQL itself. Or as they put it "Why Should You Avoid AES In MySQL?". However, if you search for SQL encryption, ...
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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? ...
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Decrypting TLS in Wireshark when using DHE_RSA ciphersuites

How can I decrypt TLS messages when an ephemeral Diffie-Hellman ciphersuite is used? I am able to expose the premaster secret and master secret from the SSL Client. Using that, how to decrypt the ...
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Does Android encryption really prevent law enforcement access?

Google recently announced that in Android L encryption would be turned on by default: For over three years Android has offered encryption, and keys are not stored off of the device, so they ...
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Does using the same encryption algorithm multiple times make a difference?

In TrueCrypt I noticed the option to encrypt a volume with multiple encryption algorithms i.e. AES-Twofish-Serpent. Would it be useful to encrypt something with the same algorithm multiple times? For ...
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Why do PGP master keys only have a single subkey, and tie certification with signing by default?

After learning more about PGP subkeys and how to split apart the roles of (S)igning, (E)ncryption, (A)uthentication and (C)ertification, I discovered that in most cases(?) a default master key has a ...
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Homomorphic encryption used for e-voting?

I was reading wikipedia about homomorphic encryptions, and one part got me a bit confused: "The homomorphic property of various cryptosystems can be used to create secure voting systems, ..." ...
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Is there anything standing in the way of email encryption going mainstream? [closed]

PGP has been around for almost 20 years, but email encryption is not used by most 'regular people'. At the moment, with Snowden's NSA revelations (which should not be a huge surprise to anyone), the ...
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Principle of asymmetric algorithm in plain english

I was giving a presentation to my colleagues about cryptography basics in which I explained about asymmetric algorithm and its use. One of the common question from the audience about asymmetric ...
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Are there any systems out there that use a one-time pad?

I'm still new to information security, but I have read a bit about the one-time pad. The point that sticks out to me the most is that it is supposedly unbreakable. Has this method of encryption ever ...
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Will my hosting provider be able to see my SSL private keys?

I'm trying to learn the best way to implement a secure web and e-mail server. Getting SSL certificates is a must, but what happens with the private keys? I've seen that you have to store them on the ...
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Checklist on building an Offline Root & Intermediate Certificate Authority (CA)

Microsoft allows a CA to use Cryptography Next Generation (CNG) and advises of incompatibility issues for clients that do not support this suite. Here is an image of the default cryptography settings ...
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Computationally simple, lightweight replacement for SSL/TLS

Target hardware is a rather low-powered MCU (ARM Cortex-M3 @72MHz, with just about 64KB SRAM and 256KB flash), so walking the thin line here. My board does have ethernet, and I will eventually get ...
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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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What changed between TLS and DTLS

What did the DTLS (TLS over UDP) authors have to change so that it could run without TCP? Bonus points: Do any of the protocol difference affect the way it should be used, both in terms of interface ...
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Is Signal a secure and secret way to communicate via voice calls?

Signal (former RedPhone) provides end-to-end encryption for your calls, securing your conversations so that nobody can listen in. But really, how is the probability that a voice conversation is ...
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How secure is 7z encryption?

I have a text file in which I store all my bank details. I compress and encrypt it with 7-Zip using the following parameters: Compression parameters: Archive format: 7z Compression level: ...
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Doing a dictionary attack on RSA if you have the public key?

I'm trying to learn exactly how RSA works. Currently I have a very, very simplictic overview that goes like this. Having the public key allows you to encrypt things. Encrypting the same message ...
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OS with encrypted RAM?

Are there any applications, JIT frameworks or operating systems that focus on encrypted virtual memory, or perhaps virtual machines that do something similar? I know there are processors (albeit old, ...
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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 ...