Questions tagged [encryption]

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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5answers
3k views

Password Storage - Self Encryption vs Hashing?

Self Encryption: Encrypting a password using the password itself (as a symmetric key). Basically, by doing this, I'll get random data as an output. Now, in order to retrieve the password from this ...
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Is AES encrypting a password with itself more secure than SHA1?

This isn't really a practical question, but more a question of curiosity. I heard a CS professor recommend stepping up from md5ing passwords not to SHA1, but to AES encrypting the password using ...
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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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1answer
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Which is the Best Cipher Mode and Padding Mode for AES Encryption? [closed]

As per PCI-DSS 3.4 requirement: For storing Credit Card Data Strong Cryptography should be used. I decided to use AES Encryption which is a strong and mostly recommended crypto for encrypting Credit ...
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Is Bitlocker secure enough for portable storage devices?

I have recently lost a USB flash drive that contained some important information. Fortunately, it was protected by Bitlocker. I felt the impulse to ask exactly how secure it is. Most answers on this ...
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3answers
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Tell people that I can encrypt emails

I know that it is still not very easy to use PGP for an average user. However, the situation is improving (there are some easy plugins that can even nicely integrate into your GMail webmail). In ...
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7answers
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Can you say that since one time pad encryption is unbreakable, it is the best if used properly?

I'm currently reading about one time pad encryption, and I have a question. They say OTP encryption is unbreakable, and this can be proved mathematically. This is provided that the key used is truly ...
30
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9answers
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Is encryption in HTTPS done by the browser or by the system?

This may be a common sense question, but I am not able to find any documentation on this after searching on google for a long time When browser makes a HTTPs request, does it encrypt the data then ...
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How are ProtonMail keys distributed?

There is a service called ProtonMail. It encrypts email on the client side, stores encrypted message on their servers, and then the recipient decrypts it, also on the client side and the system "...
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2answers
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What's the difference between end-to-end and regular TLS encryption?

I've been told that WhatsApp implemented "end-to-end" encryption. In the grand scheme of things, what does this actually mean versus, say, another service which does use HTTPS, such as this website (...
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Do spaces in a passphrase really add any more security/entropy?

I often see passphrase suggestions written as a sentence, with spaces. In that format are they more susceptible to a dictionary attack because each word is on it's own as opposed to a large unbroken ...
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Forced into using a static IV (AES)

We've had to extend our website to communicate user credentials to a suppliers website (in the query string) using AES with a 256-bit key, however they are using a static IV when decrypting the ...
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2answers
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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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What ciphers should I use in my web server after I configure my SSL certificate?

There are many great questions that ask what is the best certificate to use for a website; but once the certificate is purchased, there is also the possibility to choose or edit the Cipher list. ...
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What role does clock synchronization play in SSL communcation

We've recently implemented WS Trust security over SSL for our client / server communications. Our application is used by thousands of our customers, spread out all over the world. One of the ...
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How to secure passwords over HTTP?

Say my password is abc. I want to send it to the server over HTTP. I could send it in plaintext and let the server hash it and compare it to the entries in its database, but then anyone that can see ...
29
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3answers
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Can I use WhatsApp to securely send public key, symmetric key and private key?

I am asking this because WhatsApp says it is end-to-end encrypted. Are there any problems with sending a public key through WhatsApp? There might be some objections to sending symmetric and private ...
29
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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 ...
29
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1answer
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Are credit-card security codes theoretically insecure (if not entirely broken) already?

I was reading the Wikipedia article on Card security codes (CSC, CVD, CVV, CVC, V-code, SPC, CID, CV2, CVN2, CAcronym2, etc) and a certain assertion caught my eye (emphasis mine): The CSC for each ...
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Which host key algorithm is best to use for SSH?

When you first connect to an SSH server that is not contained inside your known_hosts file your SSH client displays the fingerprint of the public key that the server gave. I found from this question ...
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Do secure phone lines exist?

I could be out of context here about security, but , I would like to know if phone lines or phone calls over VOIP could be made secure . I know that Skype and other VOIP service providers have to ...
29
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3answers
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Are there any known vulnerabilities in PPTP VPNs when configured properly?

PPTP is the only VPN protocol supported by some devices (for example, the Asus RT-AC66U WiFi router). If PPTP is configured to only use the most secure options, does its use present any security ...
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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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Use multiple computers for faster brute force [duplicate]

I've watched Mr. Robot lately and can't stop thinking why it was so hard to decrypt files encrypted using AES encryption with a 256-bit key. Let us say the only method to find the key is through brute ...
28
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Encrypting a few TB of Data [closed]

I'm planning on encrypting a large media library of mine. Have looked into different solutions, but thought I should ask the community what your thoughts are. I don't want to encrypt each file ...
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6answers
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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 ...
28
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9answers
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Recover deleted file despite full disk encryption

This might be a stupid question, but I'll go ahead and ask it anyway. Say I am on Windows and I create a file, secret_financial_plan.txt, where I store all my company's black market financial ...
28
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2answers
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How is it possible for user's password to be changed after storage was encrypted? (on OS X, Android)

There are built-in functionalities to encrypt a storage on OS X (FileVault) and Android. On OS X: to enable encryption current user must have a password protected account. After enabling the ...
28
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7answers
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Why encrypt data in memory?

I saw that KeePass not only encrypts its password-database-file, it also can encrypt the passwords it holds in memory. This is just an example. I thinking of a new project dealing with sensitve / ...
28
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1answer
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What does this say? It's in MD5 [closed]

Some one sent this to me and I have tried to figure it ouut on my own. But have not been successful. Can you help figure out this, he said it was in MD5... 1ce67f05968d51656eb71f13368f0b2d
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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 ...
28
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3answers
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Generating one time URLs which can be revoked

I have a requirement to generate a one time use URL which should have the following features: As the URL query parameters may contain sensitive information, it should be encrypted (on top of https ...
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3answers
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What does it mean for a digital certificate to be “signed”?

When someone says that a particular digital certificate (like an SSL cert) has been "signed with a key", what does that imply? Does that mean the certificate simply includes a key that should be used ...
28
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3answers
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Why is plain dm-crypt only recommended for experts?

I am curious about the following claim from the Cryptsetup FAQ: 2.4 What is the difference between "plain" and LUKS format? First, unless you happen to understand the cryptographic background ...
28
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1answer
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iOS Encryption Details

Following on from this question, what resources are available relating to the technical specifics of how apple implement encryption on their iOS 4.x series devices? The Apple marketing material here, ...
27
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8answers
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Should firmware images for IoT be encrypted for security reasons?

When working with Internet of Things devices, is it recommend to obfuscate or encrypt firmware images pushed to clients? This to make reverse engineering harder. (They should be signed of course)
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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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How can I determine the encryption strength of an SSL connection

If I've connected to a https url, how can I determine the cipher strength of the connection? My understanding is that after the asymmetric public-key handshake the information is encrypted using a ...
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4answers
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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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Why did TLS 1.3 drop AES-CBC?

I was watching this video about TLS 1.3: "Deploying TLS 1.3: the great, the good and the bad (33c3)" and was somewhat surprised to see that in their effort to provide "fewer, better choices" they ...
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Is EncFS secure for encrypting Dropbox?

I've encrypted my Dropbox folder with EncFS according to a few tutorials I found on the web, advocating this approach. But I've found the following critical statement concerning EncFS's security in ...
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2answers
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Break the popularity contest crypto

There is a very interesting puzzle on the Programming Puzzles and Code Golf site to Rearrange pixels in an image so it can't be recognized and then get it back. I understand that this is not ...
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4answers
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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 ...
27
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1answer
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Is a password manager better than an encrypted file for storing passwords?

For any passwords other than websites I log into regularly (such as Gmail, Facebook, etc.), I use apg to generate a random 20 character password. I then add that password and a username or email ...
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3answers
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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 ...
27
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2answers
2k views

Does versioning an encrypted file make it less secure?

Suppose I use KeePassX as a password manager, and I store the kdb file in Sparkleshare folder as a way for backing up and syncing with multiple devices. The kdb file in itself would be encrypted, but ...
27
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3answers
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How to encrypt database connection credentials on a web server?

OWASP advise against storing DB credentials in plain text: https://www.owasp.org/index.php/Password_in_Configuration_File However, they don't provide suggestions of how to encrypt the DB access ...
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4answers
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Flaw in encryption through pseudorandom number stream (from PGP documentation)

I was reading PGP docs and came upon a part written by Phil Zimmermann (PGP's creator) that piqued my curiosity: When I was in college in the early 70s, I devised what I believed was a brilliant ...
26
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4answers
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Cracking double encrypted router password?

I noticed in the html of my router this parameter: form.addParameter('Password', base64encode(SHA256(Password.value))); So when I type in the password passw I get this via sslstrip: 2018-09-25 21:...
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4answers
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Is email encryption, as claimed by ProtonMail, possible?

Is it possible to create a Web service that encrypts all messages, such that only the writer, and the person to whom the mail is sent, can read it? In other words, is the theory behind ProtonMail ...