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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Encrypting a huffman encoded file

I wrote a huffman encoding program that can compress and decompress files. The file contains a header which contains information that allows me to retrieve the huffman tree. I wanted to add a simple ...
2
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1answer
134 views

Is it possible to design a system where the client doesn't have to trust the server?

When you are using services like chat, file sending, exchanging etc., you always have to trust server providing these services. The only way to use services without having to trust third party is to ...
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1answer
37 views

Which encryption technique should be used for users name and passwords in my notebook [duplicate]

i writing all my passwords and users names on my notebook emails,amazons,facebook. and i have really Nosy little's brothers that will probably look at my notebook when i am not around, which ...
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2answers
193 views

Which encryption technique should be used for cloud computing data transfer?

I want to setup my application for cloud computing for Software as a Service. There is going to be a lot of data transfer between my server and client, to and fro. The technique I have envisaged is: ...
6
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1answer
243 views

How could a system be zero-knowledge?

I'm actually interested about zero-knowledge storage system. Those system where the storage provider claims he can't have any access to the data stored. As far I know, the data are encrypted using a ...
0
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1answer
42 views

Forward Secrecy not supported with referenced browsers?

I am running a scan against one of our servers from the Qualys SSL tester site and it says that my server "does not support forward secrecy with the referenced browsers". What exactly does that mean? ...
2
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2answers
165 views

How can I secure the secret key?

I am a bit confused about securing the secret encyption key. Here is the scenario: I need to encrypt some data (file) This data will be read by a program (say written in C/C++). Both the program ...
2
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1answer
101 views

How does Mylar ensure encrypted data remains secure even if the live app code is compromised

Because Mylar does the decryption in the browser, the key is never stored on the server. Nice. This moves the threat to the browser, where, if the attacker is able to get a malicious script to be ...
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1answer
35 views

updatedb and encrypted home folders: Does it store unencrypted file and folder names somewhere?

When you encrypt your home folder in Ubuntu and Debian, it protects not only the file contents but also the file and folder names. Yet I see that updatedb and locate works in Debian. When I run ...
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0answers
32 views

Possible CPA or CCA attack when using AES-CBC mode under the following situation?

Both client and server know a shared key in advance. Both sides us EVP_BytesToKey() derive a pair of same key and same IV. Then, client and server start transferring data encrypted by AES-CBC mode ...
0
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1answer
67 views

encrypted lookup-keys for key-value store

I'd like to use a key-value store (cassandra, redis, ...), but I don't trust the server. The clients have a shared secret, and I'm using that to encrypt the stored values. But what is the proper way ...
1
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3answers
417 views

Protect database data from everyone, including sys admins, etc

One of the things that has always bothered me about simple database data encryption: If the server is compromised, the database is effectively compromised. The attacker can use the same code as the ...
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1answer
69 views

Encrypting folders with flash drive key?

Is there any way to have a flash drive encrypted and it will only open with one computer that has the key in it?
2
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2answers
133 views

How can I secure my api to avoid copying?

Im building an app which should receive data from my server. The Api should be a PHP based script which provides the data as JSON. However I want to keep the data private and it should only be ...
0
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1answer
159 views

Are temporary files an issue when opening and editing an encrypted 7z file?

I am new to security and encryption. I want to store important information like passwords and pin codes so I don't forget them. So far I have been using LastPass but I would prefer a solution I ...
0
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1answer
374 views

How are TLSv1.0 ciphers negotiated as TLSv1.2?

I'm a little confused about something I am reading in Bulletproof SSL. "TLS 1.2 is the only protocol that allows suites to define their PRFs. This means that for the suites defined before TLS 1.2 ...
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2answers
99 views

Are digital signature algorithms subject to the same types of attack as public-key encryption algorithms?

I understand that digital signatures are usually implemented by encrypting a message digest with a private key, decrypting the resulting signature with a public key, and verifying that the message ...
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2answers
115 views

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 ...
49
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6answers
16k views

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 ...
2
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1answer
47 views

Possibility of using CA as an attack point by governmental organizations under their pressure

I was always concerned about the model of trust behind CA stuff we use . Well, for most of us, it is OK to trust them, since they are reliable organizations with a bunch of solid experience. ...
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1answer
252 views

Security margin of a winzip, Winrar password of 64 characters against GPU cracking

what s the longterm security margin of of a winzip or Winrar file encrypted with aes-256 and a password consisting of 64 completely random characters set a-z 0-9 and other printable special ...
2
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1answer
159 views

Is encrypting something more than once safer than hashing more than once?

I am aware of the implications that hashing something more than once correctly will increase the security of a system, but doing it incorrectly will decrease it, as noted here and on various other ...
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2answers
59 views

Identifying/decrypting hashed/encrypted data [closed]

This weekend I took part in an security challenge. I had great fun doing it but i found a huge gap in my knowledge that I'm really keen to fill and hope someone here can help get me pointing in the ...
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2answers
1k views

Extract AES key by comparing plaintext and encrypted data

Is there a kind of analysis which would enable me to get AES key which was used for encrypting arbitrary data while I have both original and encrypted version of data ? The problem is that the AES ...
2
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1answer
102 views

Drawbacks to only using TLS 1.2 ciphers in OpenSSL

I understand you would not want to do this as it would limit compatibility for older devices and platforms. However if someone were in an all TLS1.2 environment, say a very well managed internal ...
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3answers
91 views

Why do we use such a redundant language (English) for network communication? [closed]

I have heard throughout the internet that English is incredibly redundant. So why do we turn English messages in to a cipher which is then, from my understanding more vulnerable to letter frequency ...
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1answer
26 views

Choosing right way to secure access to server access via socket

I have an application running on a server, that has an exposed socket to the Internet to communicate with client that is/are application(s) on a phone. How would one go about properly securing the ...
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3answers
113 views

How are HSMs used in payment processing on the server?

I came to know recently that HSMs are used in credit card processing on the server side but since I don't work in that space and stumped as to why its needed. I can see it used in an ATM machine - ...
4
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1answer
100 views

Is there a secure way to create and distribute Shamir Secrets?

This Shamir Secret sharing utility consumes the secret key, and then generates N keys that must be manually distributed to each person. This is probably fine for most low-security situations, but not ...
2
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2answers
315 views

Easiest solution for automatic encryption of files on Dropbox?

I don't trust Dropbox to keep my files secure. In fact, the same goes for all the other file clouds. What I'd like is a easy and cross platform means of encrypting files that I add and read from ...
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2answers
170 views

Using different algorithms to slow down GPU password cracking [duplicate]

I have some job related files I have already compressed with 7Z. I have protected each with good 10 character passwords consisting of upper, and lower cases, numbers and special characters. And I ...
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1answer
295 views

Using AES as a Stream Cipher

I need to send a lot of small messages that are usually between 128 bits and 256 bits long, and each message is encrypted with a separate 128 bit AES key. Therefore, to send each message with the key ...
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1answer
56 views

Entering payment information in Android Apps

I'm concerned how android apps that integrate payment processing deal with secure financial information.When purchasing through these apps the apps show the Webpage of the bank asking for credentials. ...
2
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1answer
98 views

Are all TCP connection protected by IPsec?

I hope this question fits this stackexchange: From what I understand, IPSec takes care of encrypting everything above the IP layer (transport, application). Does that mean that if I open a socket ...
2
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0answers
171 views

Some http requests are not send encrypted by vpn! Why?

I subscribed to a VPN service recently, and installed wireshark to take a look at the traffic sent from my computer. Practically all of it goes through UDP protocol, encrypted. But there are two HTTP ...
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0answers
51 views

Payment Application Integration - Encryption or HMAC

Doing an integration with an online payment provider. Payment provider will be making a web request to my server to provide some information about the basket content. On my end there's no payment ...
2
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2answers
57 views

How to identify Encryption algorithm for data coming in field/attribute values of an xml

I have data coming in the form of XML with certain XML attributes being encrypted. I am very new to encryption/decryption. So I would like a detailed explanation on how to find the encryption ...
4
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2answers
119 views

How does an insecure RNG affect cryptography, and how do I measure the corresponding loss of security?

Suppose a given random number generator has poor entropy, and is compressible by any compression algorithm (zlib, bzip2, lzma, etc). Specifically the issues with this RNG are: Bad entropy Bad seed ...
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3answers
106 views

What's the most secure way to send information from one device to another?

I need to send sensitive information from one piece of hardware to another. I was thinking wifi, but if someone obtains the password, it wouldn't be encrypted. I don't think you can use ssl unless ...
5
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1answer
251 views

How is ZixCorp able to provide email encryption without a password?

I am trying to understand how/if an email I received is being encrypted. A financial institution sent me a verifiable email (i.e. not phising) asking me to fill out a pdf form to complete a ...
2
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3answers
153 views

Adding photos to Truecrypted, airgapped laptop from camera safely

I have a Truecrypted, airgapped (no internet connectivity at all) laptop that I use as a completely secure computer for sensitive files. I want to add images from my iPhone (I know), camera or other ...
0
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2answers
98 views

How to combine a key and a password in practice

Alice wants to encrypt her data. She is not comfortable with using only a password. While she prefers to use a properly random crypto key, she isn't confident she can protect the key file from theft ...
0
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0answers
86 views

What else do I need to secure my data in an encrypted non-system drive?

I have to use an almost seven years old laptop running Windows 7 ultimate and want to encrypt my hard disk to protect my private data (e.g. documents, pictures, Dropbox, etc.). I encrypted a ...
0
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0answers
40 views

Composing and Inverting Symmetric Encryption Keys

First Question: Using a symmetric encryption algorithm E on a message M, users usually send E(M) to the recipient and then the recipient will compute E^-1(E(M))=M to retrieve the message. If M is ...
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2answers
70 views

Is there a secret-sharing public-key-encryption-based service? [closed]

I need to share some sensitive information with someone else who can only communicate via E-mail. I don't love the idea of sharing this information freely over email in plain text, so I was ...
1
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2answers
141 views

Will an IP packet to the own IP address ever leave the computer? [duplicate]

I am working on a system that consists of several applicaitons communicating with each other. Some of these applications will run on the same server and some will run on a different one. So there is ...
2
votes
3answers
99 views

How can DH provide a known secret to two parties over an unencrypted connection without it being intercepted via MITM?

Without using Private and Public keypairs, i do not understand how Diffie-Hellman is able to generate a secret key between two parties on the internet without passing something between that could be ...
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2answers
159 views

Can ISP use MITM attack to “break” encrypted traffic?

Use connection of A and B as an example. Their communications were encrypted by Public Key Encryption. Before they exchange their public key, ISP MITM attacked. A got "B"'s public key (ISP generated) ...
0
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2answers
71 views

Is server-side access control sufficient or should I encrypt querystrings

I've got an ASP Classic system that passes around sequential ids corresponding to keys in the database. I had gotten an encryption module (chilkat, an activex control) that I was using to encrypt and ...
5
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1answer
112 views

Is a Linux environment PCI compliant if the swap file is not encrypted and PANs are loaded into RAM?

Is a Linux environment PCI compliant if the swap partition/file is not encrypted and PANs are loaded into RAM by an application?