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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encrypted emails and keyservers

I read that encrypted emails are secure, cause only who has your public key can decrypt it. I also read that it's a common thing to upload your public key on a keyserver. But if my encrypted email ...
10
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1answer
12k views

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 ...
0
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2answers
220 views

What was the Lavabit's backdoors to their customers' e-mails? [closed]

There has been some talk about the Lavabit's case. New info was published today, but not important. I'd like to know how Lavabit worked. First I thought they just did something with OpenPGP. Then I ...
6
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2answers
5k views

What is the difference between SSH and IPsec?

There seems to be similar encryption going into both. They both use asymmetric (RSA, elliptic curves, etc) for the initial key exchange, then go to some symmetric (AES, Blowfish, etc) protocol. I'm ...
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4answers
980 views

Achieving End to End encryption with TLS

The scenario is that a client browser (eg: a user trying to log in to a bank website) needs to be able to view certain sensitive information that resides in a mainframe sitting in the Internal network ...
3
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2answers
1k views

Using AES to encrypt user data

I know next to nothing about cryptography, and I'm basically just looking for someone to look over what I'm doing and tell me if I'm screwing up. I have the user entering in some sensitive ...
6
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2answers
7k views

How do I decrypt an Adobe Triple DES ECB-mode encrypted password?

So as you may have heard, the Adobe user database with 130 million records was leaked recently. I want to find out what password I used for the Adobe account I created to make sure that I'm not using ...
2
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1answer
876 views

How can I secure IP Multicast traffic?

I'm interested in securing IP Multicast traffic for content that will be sent globally with several low bandwidth receivers. I understand that simplified Broadcast encryption takes N public keys ...
3
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0answers
149 views

BSD encryption advantages [closed]

If someone who knows about the BSD project has a moment to answer this, I'm wondering a few things about the encryption used. It's more than what I'm finding in the docs and on Wiki/Google (even the ...
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6answers
2k views

Is it useful to protect hashed password with encryption?

Imagine that I am hashing the users' passwords with a random, long enough, salt, using key stretching, and a secure hash. Would it be more secure to finally encrypt the hash with a symmetric key?
2
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2answers
154 views

How safe is Money Toolkit?

Money Toolkit is a smartphone app that can alert you to your balances and transactions across multiple accounts. I was reading their site and whether their practises are as secure as they claim to ...
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3answers
11k views

How long (in letters) are encryption keys for AES? [closed]

How long is the encryption/decryption key for an assymetric algorithm, such as AES? If I use AES 128-bit, how many characters should I type in for my key? What about AES 256-bit? Edit: Here is why I ...
0
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4answers
239 views

Is it possible to digitally sign information with a password?

I'm creating a cloud storage service and need to have the ability to provide reliable security for clients. In my previous question, I used a different schematic and said I would post a new question. ...
4
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1answer
731 views

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 ...
1
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1answer
492 views

What is the best practice to save encryption and decryption method in an application?

Almost all the application regardless of their nature and purpose are using encryption to secure sensitive data to be saved to database, if the user using a method to encrypt a file (for instance an ...
0
votes
1answer
197 views

vsftp encryption algorithm

I want to configure VSFTP for ftps protocol and it has some choices to select the encryption type: tlsv1, sslv2, sslv3. I read that tls version 1 has some security issues but in the man page it says ...
2
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2answers
437 views

Lightweight block ciphers definition

I've read in many papers something that looks an specialisation of the block ciphers calling them with a lightweight tag, but I couldn't found a definition. If I understand correctly, those ...
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1answer
2k views

How does DES provide confusion and diffusion? [closed]

I know that Data Encryption Standard (DES) provide strong security but I want to know how does it provides confusion and diffusion?
4
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3answers
2k views

symetric key encryption vs hashing

This is a fascinating document: top 100 passwords from adobe breach I have a question about one part of it: However, thanks to Adobe choosing symmetric key encryption over hashing, selecting ...
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0answers
199 views

Encrypted chat using any smartphone. Is it legal? [closed]

Here's my case. We have written app for Android smartphones which allows users to exchange secured cipher messages. For key-exchange we're using elliptic curve 112 bits, for messaging we're using DES ...
7
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2answers
988 views

An analysis of storing hints for passwords?

What are the security implications of asking users to provide password hints? What are best practices for storing user hints? What research has been done on using user-supplied password hints to ...
1
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1answer
3k 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 ...
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1answer
2k views

Is it possible to encrypt WiFi connection?

Is it possible to encrypt (encrypt traffic) WiFi connection from my laptop to my router? If anyone of you did it? How I can do this?
0
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2answers
71 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 ...
3
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1answer
593 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 ...
4
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3answers
555 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 ...
0
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1answer
751 views

How do I determine S/MIME encryption used?

From what I understand it seems that S/MIME uses PKCS #7 which can handle various different types of encryption. How is the choice of encryption method made by the e-mail client and how do I know what ...
2
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2answers
3k 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 ...
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2answers
157 views

Is this adaptation of using a One Time Pad safe?

For example, lets say there are two people named, Bob, and Jim. Bob wants to send Jim a long secret message, and he decides to use a OTP to encrypt his message. Both Bob and Jim know a secret ...
0
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1answer
222 views

What is the weakness of OFB in 8bit mode?

I'm currently trying to understand the difference between "regular" OFB with full-block feedback and OFB with 8-bit feedback and, in this context, the difference between this two modes regarding ...
4
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5answers
4k views

Is it possible to restrict USB keys to only certified ones, and block that key's access on other computers

I am working on security for an organisation, we have purchased some encrypted USB keys but wanted to stop any employees leaking data. is there any way to stop their laptop accepting any key but the ...
2
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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 ...
3
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0answers
278 views

Routing Protocol Encryption

As far as I know 'newer' versions of routing protocols support authentication between routers. What about encryption and integrity checks? Some implementations like this one from Cisco use MD5, which ...
3
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1answer
611 views

SSL/TLS in Jabber

Just wondering: is entire traffic between me and the Jabber server I use encrypted, or only login and password? Given that the server supports encryption, and my IM client is configured to ask for ...
3
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1answer
488 views

What is the best way to manage gpg keys across multiple devices?

I have a desktop computer and a laptop computer both running Debian. All of the devices have encrypted hard drives. I also have a phone running Cyanogenmod/Android. What is the best way to manage ...
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2answers
149 views

when integrity is implemented using encryption arises any problem?

when confidentiality is implemented using encryption arises a problem: "how the receiver knows the message is really sent by the sent as it is claims?". when authentication is implemented using ...
0
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2answers
91 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 ...
4
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1answer
820 views

How is the iCloud keychain protected from unauthorized access?

With OS X Mavericks and iOS 7.0.3, Apple has introduced a new feature called iCloud keychain. During setup, you can choose an iCloud Security Code. This code is used when you want to grant access to ...
13
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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 ...
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2answers
655 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 ...
2
votes
4answers
391 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
184 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.?
7
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3answers
3k views

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 ...
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?
8
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4answers
4k views

Security of the KWallet password encrypting application?

According to http://gaganpreet.in/blog/2013/07/24/kwallet-security-analysis/ , the KWallet password management system is quite weak, it uses key splitting, Blowfish 56, and no salt. The key ...
4
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2answers
2k views

What order is best for nesting VPNs?

if anyone is available to give me advice on a VPN situation I'd appreciate it. So the story is, I have one Swedish VPN which I trust not to log, and which I've connected to with my real IP, and I've ...
2
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1answer
994 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... ...
1
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1answer
552 views

Why are the first 16 bits of the message digest not encrypted in PGP? [closed]

The first 16 bits of the message digest in a PGP signature are translated in the clear. As we know, sending something in clear text does not sound like a very good idea from a security point of view. ...
16
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6answers
10k views

How do I prevent copying of my PDF files?

One time while I was printing my documents at a copy center, I saw they dragged-and-dropped my PDFs from my flash drive to their desktop. How do I protect my files without using password? Is there a ...
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 ...