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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How does Dropbox keep files secure

I have read that Dropbox encrypts all the files that are uploaded with a single encryption key. Where is this key stored and why do they bother encrypting the stored items if they just store the key ...
14
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4answers
715 views

Database Encryption Security

I am encrypting and decrypting my database data from my web applications API. If my web server is compromised, what is to keep someone from using that same method to retrieve the data? For example, ...
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1answer
2k views

Multi-key encryption algorithm [duplicate]

I am looking for a way to do multi-key encryption with the set number of decryption keys. The goal is to take a file, encrypt it and generate several decryption keys, in order to decrypt several (not ...
-1
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2answers
256 views

How to store my contacts encrypted?

I use KeePass for storing my passwords. What should I use if I want to store my several hundred contacts (name, phone number, email, etc) encrypted?
5
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2answers
7k views

Is it safe to store password in PHP session?

I need to do some encryptions in the private zone of my website and I want to bcrypt the user's password. Is it safe to store the password in the session when user does the login, so that I can use ...
1
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0answers
120 views

Techniques for web-user communication across an untrusted server

I'm designing a web-based notification framework (i.e. a user can subscribe to updates from a service or another user) where communication between users is encrypted. User-to-user communication on ...
0
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2answers
70 views

Is there a way to safely exchange two different informations like a sliding door?

In real life it would be like putting two items at the opposite sides of a sliding door, you turn it and they can be exchanged safely. Not only that, if the door is made out of glass, you can pretty ...
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2answers
573 views

Can I encrypt the packets that are sent to my router?

Is there a way to encrypt HTTP traffic to avoid man-in-the-middle attacks? I use Google Chrome.
2
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1answer
251 views

Design of Initialisation Vector

I understand that an IV (initialisation vector) should be both unique and unpredictable, but I have found little guidance as to which is most important. For an AES cipher I have a block size of 128 ...
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3answers
528 views

Fully encrypted social network theory

I have this idea about building a social network that stores all its data encrypted. The idea is that a member's data is stored on multiple 'base servers' (of the member's choice). Each member has 3 ...
3
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1answer
551 views

Symmetric encryption with different encryption and decryption keys

In the book, Applied Cryptography by Bruce Scheier, in the foundations chapter he defines symmetric encryption algorithms as algorithms where the encryption key can be calculated from the ...
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2answers
2k views

What's the limit on the size of the data that public-key cryptos can handle?

Someone mentioned here that asymmetric encryption might not be appropriate for bulk data and gave an example of RSA with 100 bytes. Of course, I understand that it was a rough example. But it made me ...
3
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2answers
347 views

Is splitting up an AES Key a problem?

I'm wondering if it would be a problem to split up a 256 bit AES-Key into two 16-Byte blocks and distribute it, to implement some kind of a four-eyes-principle (you need two persons to decrypt a ...
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1answer
1k views

AES key management

I am encrypting a secret in a db field. I am encrypting using AES with a 256-bit key and a random IV per encryption. They AES key is hard coded in the code. Each IV is stored in clear in another ...
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2answers
518 views

S/MIME verification

I am getting emails with smime.p7s attachments. when I look at my mail on my Linux box, I can see base64 encoded block in mail body. I can extract that block and open it on Windows using certmgr and ...
0
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2answers
90 views

Secure system generated symmetric keys

I'm developing a system that manages and shares user passwords (which are encrypted using user generated symmetric keys). But of course a big concern is the user losing their symmetric key and the ...
12
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4answers
2k views

At what point does adding more iterations to PBKDF2 provide no extra security?

If my true passphrase is used only to generate a hash which is used as the cipher's actual key, doesn't that mean it's possible to try and brute force the cipher itself? I know it would take an ...
2
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1answer
317 views

Kismet Output Shows 3 Possible Encryption Options, Which one?

Ran into an interesting situation with Kismet and Airmon-ng while observing a client wireless network. Basically, I'm observing the network using airmon-ng, and I have my BSSID and frequency set to ...
4
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2answers
3k views

How does VPN encryption work?

I've been searching and searching, but I can't seem to find a good-enough technical explanation. From what I've gathered, there are two "things" able to secure VPNs: 1) Pre-Shared Key: This handles ...
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2answers
616 views

May I `store` the password, by making it the key in AES-256?

I would like to seek for another way to save the credentials, which is used to verify the user trying to login, into my database. I came up with this idea. Since I believe that even knowing a ...
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2answers
473 views

the Informix password crack

I get some hash like: username sowainformix salt 7307821250330563328 hashed_password HaHvvzanjp_lPZgHLu0KHquN.Q4t98EF48csXk1QTJs hash_type SHA-256 updated flags ...
2
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3answers
352 views

Protecting personal documents in cloud

I want to keep my personal documents in cloud e.g. Dropbox. But I want some of my documents be encryted and password protected, such that: 1. even if my Dropbox gets hacked, those documents still have ...
1
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1answer
181 views

google states connection is encrypted. Should I change that?

"The connection to www.google.com is encrypted using RC4_128 with SHA1 for message authentication and ECDHE_RSA as the key exchange mechanism". This is on my google search bar. Is that o.k.?
2
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4answers
205 views

How does Eve monitor and obtain ciphertexts?

Throughout my readings on cryptography, Eve is always assumed to have the capability to be a passive listener and obtain every message exchanged between two communicators. How can one demonstrate ...
3
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1answer
4k views

How is the HMAC key exchanged?

Just wondering about this. Does it need a PKI to work?
2
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1answer
974 views

Is my RSA signed data secure?

So with all of the FUDD (fear/uncertainty/doubt/disinformation) going around about RSA in light of Snowden leaks and other discoveries about backdoors into PRNG, I'm uncertain what this means to me... ...
2
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1answer
2k views

Open source video conferencing software with encryption [closed]

A couple of friends and I are looking for an open source video conferencing software. We'd like to run the server on a Debian box, but the clients are Windows machines. Most importantly, it should ...
0
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1answer
185 views

Corrupt password being pulled from wireshark data?

Hello everyone, I currently have a pcap file that contains an unencrypted Telnet session, and when I trace the TCP stream the password is in a format like so: pas...ord (please note ...
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1answer
624 views

Expiring Decryption Key

So, I'm just a programmer -- I don't know much about cryptography so bare with me and my lack of knowledge in this realm. But essentially, I'm wanting to cache data that could be potentially volatile ...
7
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2answers
2k views

Encrypting something with multiple keys such that k out of n keys are needed; what's it called?

I am trying to find information on how to encrypt something in such a way that there are n keys, and k of them are needed for decryption. However, I have been searching Google for half an hour but ...
5
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1answer
416 views

Does encrypting the same file twice with two different keys present a security risk?

Suppose you have a file that you wish to maintain two encrypted versions of, each version encrypted with its own (randomly generated, sufficiently long) key. The actual method of encryption is by ...
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2answers
310 views

Would multiple exposed bcrypt hashes of the same UUID v4 with random generated salt be too insecure?

I'm looking into implementing an ownership check on JSON objects and want to avoid going back to the database to ensure ownership of said object/record (i.e., to prevent a user from updating an ...
0
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1answer
212 views

Mac OS: keylogger vulnerability & FileVault 2

I'm configuring my mac and encrypting my disks with FileVault 2. As the boot disk is encrypted at startup I have to login via the EFI partition before the OS will boot. From my understanding, most ...
0
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2answers
860 views

Does using Bcrypt to encrypt credit card numbers satisfy PCI compliance?

I understand that using MD5 is not safe and is not PCI compliant. Does using BCrypt satisfy PCI compliance
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2answers
862 views

Is there a way to configure WPA2-PSK to provide Forward Secrecy?

Is there a way to secure an wireless connection against a decryption attack where the PSK is known (E.G. Airdecap-NG)? Is it possible to configure Forward Secrecy on 802.11 Wireless Connections?
2
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1answer
464 views

Does any PXE/Full disk encryption password concept like this exist?

This question may just show a distinct misunderstanding of things on my part, and I apologize if it is, but I thought I'd put it out here as I don't know where else to ask. I've been thinking about ...
4
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2answers
382 views

Totally secure public key distrubition

Public-key cryptography secures communications provided that you use pre-shared public-keys. The problem is how to share these public-keys while maintaining authenticity? How can we be sure that ...
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2answers
235 views

Can any asymmetric algorithms work with only a key-sized amount of randomness?

With 397 rolls of a fair 6-sided die (not my favorite use of time, but certainly not infeasible), I could generate more than 1024 random bits. Could I use those bits to generate a keypair that could ...
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3answers
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Can I use an AP “Bridge” with password to imporve security over an open, unencrtyped WiFi signal?

I have access in my neighborhood to an open, unencrypted WiFi signal but I am leery of using it because of security reasons. I don't want to let my username, passwords or credit card numbers ...
2
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1answer
86 views

Is the following environment contained?

I would like to make sure that my working environment is contained (prevent data leaks meaning I don't want temp file or traces from files I have worked on). I am about to create a usb key with the ...
9
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4answers
2k views

Is it safe for GPG to compress all messages prior to encryption by default?

By default, GPG compresses text during encryption. Additionally, RFC 4880 says: 2.3. Compression OpenPGP implementations SHOULD compress the message after applying the signature but before ...
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2answers
422 views

How to defeat CRIME, BREACH, TIME etc… server side (without sacrificing compression)

I am writing full-stack server side software and I have been researching CRIME attacks and it's relation to SPDY header compression as I am implementing the server side codecs for it at the moment. ...
4
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3answers
2k views

How about preventing CSRF this way?

According to Cross-Site Request Forgery (CSRF) Prevention Cheat Sheet , the recommended solution to protect web site from CSRF attacking is to implement Synchronizer Token Pattern. And This requires ...
3
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2answers
303 views

Is it true, that using symetric encryption, if attacker knows encrypted text, original message, and algorithm means he can calculate the secret?

I am a newbie in the security field, so sorry for the naive question. In my understanding, using symetric encryption, if attacker knows encrypted text, original message, and algorithm means he can ...
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1answer
132 views

Oracle database privileges [closed]

I have a 10.2.0.5.0 Oracle Database and a list of users who i need to grant some privileges to (Mainly to generate reports and so on). I used impersonation, which means i created one Oracle user so ...
2
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1answer
650 views

Which products are affected by NSA's ability to crack pseudo-random-number generator Dual_EC_DRBG? [closed]

After reading this article about RSA advising its customers not to use the default random-number generator in its encryption products - amid fears spooks can easily crack data secured by the ...
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1answer
478 views

MySQL AES Encryption - Is it good idea to store 3rd Party Auth Tokens using AES Encryption?

I need some advice on MySQL AES Encryption. I'm developing an application which connects to various 3rd-Party APIs and retrieves the Access Tokens for the application users. These Access Tokens are ...
9
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1answer
436 views

Optimal variable sizes in the Secure Remote Password protocol

I am implementing the Secure Remote Password protocol: U = <username> --> <-- s = <salt from passwd file> a = random() A = g^a ...
6
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3answers
1k views

Using Secure Remote Password without sending the username in the clear

To initiate a key exchange using the SRP protocol the client sends the username so the server can look up the salt and password verifier. Is there a simple way to change this so that an evesdropper ...
0
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2answers
641 views

Storing email adress encrypted but deterministically

As part of an application I am developing, I am required to store user email adresses on a cloud DB. The email address is not required to be in plain text for the normal operation of the application. ...