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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Is it safe to encrypt data by simply randomizing chunks based on a permutation? [migrated]

Say I want to encrypt the following text: "Today is March the 22nd, 2015". And say want to encrypt 8-byte blocks of data using the following permutation [6,3,0,1,5,7,2,4] to swap characters at those ...
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2answers
100 views

Converting ECC Private key to PKCS#1 format

Is there any way to convert an ECC private key to RSA PKCS#1 format? I have tried converting it to PKCS#8 first using OpenSSL: openssl pkcs8 -topk8 -nocrypt -in EC_key.pem -out pkcs8_key.pem This ...
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1answer
121 views

Is this a sensible way to encrypt user data?

I want to make a site for storing sensitive user data, that retains per-user data encryption in the event that the database is compromised. This is the model I was thinking of, to give the best ...
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1answer
83 views

Is it dangerous to use the same key (RSA) for both encryption (PGP) and authentication (SSH)?

Alice wants to send an encrypted message to Bob, but she also wants to connect to Carol's server. Are there any dangers associated with using the same RSA key for both PGP and SSH (other than a lack ...
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1answer
78 views

What is the safest way to encrypt a password that can be decrypted at a later time?

In a web app I'm building, I need to use Apple's AutoIngestion tool for iTunes Connect. In this tool it seems the only way to use it is to send a password in plain text. What would be the best ...
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1answer
446 views

Why does GnuPG shrink my file after elgamal encryption?

I would like to run GnuPG elgamal encryption for at least a few minutes. The only way I can think of is to create a large file to be encrypted. So I created my file like this: dd if=/dev/zero ...
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1answer
49 views

Security at application layer

Originally asked on http://crypto.stackexchange.com/questions/24430/security-at-application-layer but was suggested to ask here instead. I saw lots of questions asking about encryption over http, ...
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2answers
52 views

Does changing the default number of iterations in KeePass (or other encryption applications) increase security?

Inspired by this question about the difficulty of cracking a KeePass database, I'm wondering if changing the default number of iterations in an encryption application (e.g., KeePass) increases ...
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1answer
31 views

What's the value of data partition encryption for database files on a postgres database server?

We're in the process of rolling out a postgres based web app, and I'm trying to understand the value of encrypting the entire database. In postgres's case, the only way to do this is store the ...
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1answer
68 views

Is it possible to prove the content of an encrypted message without disclosing the private key?

Suppose that I sent Bob a message saying, "The meeting is cancelled", and encrypted it with his public key. Could he share the plaintext with other people, without disclosing his private key (and ...
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1answer
101 views

Why my files that Encrypted with EFS in Windows 8.1 shown in Linux ubuntu?

i Encrypted my files with EFS in windows 8.1 so i logged in ubuntu and without any warning , its shown my files actually not Exactly the file but shown the path of file and the name and i can ...
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1answer
47 views

Is there any College, State or Government ID that transmits a offline verifiably encryptable data blob?

I'm looking for any way to digitally verify a user, ideally with a photo and link PII to that user. My use case is that a user will extract and send an encrypted data blob (say from a passport) to my ...
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1answer
158 views

What are the security differences between SMIME email and PGP email? [closed]

Outside of key distribution, and specific to the technical details relating to encrypted email data (message body), what's the difference between SMIME and PGP? Example comparisons Security ...
0
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1answer
53 views

WPS and WPA2 connection methods

Do clients use WPS every time when they connect to a WPS-enabled AP? Or maybe they do it just the first time and then they switch to a normal WPA/WPA2 key exchange? If the latter, it's possible for ...
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4answers
3k views

Is it dangerous to publicly share ciphertext?

Alice wants to share a message with Bob, but Alice and Bob can never be in the same place at the same time. We can assume they both know each others public keys (or agreed on a shared key, if that ...
0
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1answer
81 views

What are the best practices to store payment processor dev/API keys?

I am integrating with multiple payment processors which have their set of public/private keys. This would be used in conjuction with per user keys, to bill clients. I was wondering what is the best ...
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1answer
97 views

rainbow table for AES 256 CBC knowing IV, cipher text and plain text

I'm in a situation where I know that I have to decrypt a file encrypted using AES 256 CBC and I've the following details: I know the first 16 bytes block in plain text I know the IV (static 128 bit ...
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1answer
38 views

Using scrypt to encrypt data in a session variable

Let's say I want to store some data in the node's session, for example, like an authenticity token. Obviously I want to store it in an encrypted way if it's going in a cookie, then decrypt it on a ...
2
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2answers
196 views

What is a current best practice example of basic encryption and decryption in PHP?

I have a good working knowledge of basic security best practices (password hashing, preventing sql injection, CSRF, etc.) but am completely at a loss for finding a solution to common-case encryption ...
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0answers
38 views

How is Tresorit client-side encryption key stored and managed?

I am using Tresorit on Mac OS X and iPhone. When I am using it there is always applied client-side encryption before posting the file to cloud. The key used for encryption is AES-256 and CFB mode of ...
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0answers
25 views

Cryptsetup using TPM? [duplicate]

Does cryptsetup uses TPM? or CPUID to identify the hardware environment in order to prevent it from stealing and crack it on other PC.
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1answer
88 views

Is End to End encryption possible for all servers across the whole infrastructure?

Running into a possible situation where a client I am working with is requesting that all data that leaves the servers should be encrypted and here, we are talking of hundreds of Linux servers ...
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20 views

Why encrypt client<->server on top of TLS? [duplicate]

I want to implement TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 between my client and my server. However, someone advices me to add my own encryption&digital signature on top of it (adding a suite of ...
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63 views

“gpg” vs “openssl rsautl” (asymmetric keys) for credentials storage

I'm working in a PHP project and need a better solution to store credentials to a client's database, and I'm thinking about encryption, I put to work both gpg and openssl using asymmetric keys, but ...
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1answer
48 views

Feasibility of creating an in-memory web app (that runs from a CD-rom on a web server) for sharing self-destructing messages

This question is about a hypothetical in-memory web application that is used for exchanging encrypted messages that passively self-destruct in X amount of minutes. Here the messages would be stored ...
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2answers
108 views

How to secure sensitive information on cloud from administrator (end-to-end encryption)

When I use end-to-end encryption to secure documents and sensitive information on cloud or on computer, there is always a risk of accessing these information by administrator. For example if you use ...
2
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1answer
85 views

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'security in ...
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1answer
83 views

How to keep a reasonable level of entropy in an encrypted file?

Encrypted (or random) data, by nature exhibit a high entropy value and non unencrypted data will exhibit a low entropy value. From an attacker point of view the precense of this high entropy value in ...
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1answer
61 views

Can I create an application that can decrypt data but the administrator of the application cannot?

I have a windows application with a configuration file that contains some database passwords. I'd like to encrypt this data in such a way that my application can decrypt the data, but that the ...
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1answer
60 views

Security tradeoffs while designing a mobile Web Service API

I'm not a security expert but I want to ask about tradeoffs in a web service API I'm designing for mobile apps. It is an API which tracks users' locations so yes, the data is reasonably sensitive. ...
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8answers
4k views

Is it possible to construct a passively self-destructing message?

Is it possible to construct a message that passively degrades over time without requiring an external factor to destroy it? Things that are similar, but not what I mean: A hard drive that degrades ...
2
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1answer
118 views

Secure database password stored in an env variable

I need to somewhere store my DB password on my production environment to access the DB. At the moment the prod system is deployed in the cloud, so is the DB. The password, the username and some other ...
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1answer
89 views

Can zip files be cracked if they were split into parts and only one part was available?

I am talking here about zip files that were compressed using basic protection and those using AES protection. In both cases, if only one of the many parts of the zip were available, will it be able to ...
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2answers
176 views

Is SpiderOak truly “zero-knowledge”?

I've recently changed SpiderOak password on computer A. Because I have SpiderOak installed on computer B as well, I thought I will have to update the password on it so the application can connect to ...
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1answer
86 views

HIPAA vs. HTTPS

In the medical/pharmaceutical space as part of legal operating requirements, everyone has to comply with HIPAA standards ( http://health.state.tn.us/hipaa/ ) for moving personal medical information ...
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1answer
67 views

How strong is the performance impact of signing when using RSA_AES_256_ECDH

To encrypt web communication, I use SSL with a RSA key with a length of 2048 bit, AES key's with a length of 256 bit and the ECDH-algorithm for the negotiation of the AES key's (or to exchange the ...
2
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1answer
131 views

Why do major sites(Facebook, Google, etc) still send passwords unhashed? [duplicate]

QUICK SUMMARY: It seems like modern websites, for security's sake, should all have the client hash their own passwords before sending them to the server, who will rehash them, in order to avoid ...
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19 views

Difference between Kerberos and GDOI?

What is the difference between Kerberos and GDOI, I know first is more toward authentication and latter is more toward multicast key management, can I use Kerberose protocol in GDOI for server and ...
4
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1answer
49 views

Securing client-side data from users

So my problem, in its general form, is encrypting test questions such that a client-side testing application can access the questions while students cannot. The naive approach, in my opinion, is to ...
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0answers
22 views

KeePassX and Dropbox [duplicate]

I am currently using KeePassX on Linux to allow me to have a different strong password for each website. With this program there comes two major inconveniences: I lose access to everything in the case ...
2
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3answers
167 views

Sending an encrypted PGP email to someone who doesn't yet have my public key

Suppose I have the public key of a recipient I'd like to send an email to, and I've never sent this person an email before. Does it make sense to encrypt my first email to this recipient and also ...
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0answers
21 views

CCM instead of key wrap

Is there any instance of NIST or other encryption standards using AES-CCM to encrypt/authenticate key data? I would like to use CCM over a keywrap function, but cannot find any precedent for this in ...
0
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1answer
96 views

Secure way to encrypt (not hash) passwords?

I'm building a system that for reasons I'll outline below, can't used hashed passwords, but I'd still like to encrypt them so that it's as hard as possible to crack them, in the (unlikely) event the ...
3
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2answers
314 views

Can this modified 'Many' Time Pad be made 'stronger' by using an extrememly long key?

Starting with a one time pad say you want to encrypt some small strings like the words in this sentence but you want to reuse the same OTP key for each string so that when you encounter the same word ...
0
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1answer
60 views

Why first kerberos message is not ciphered

When analysing Kerberos exchange (and other similars as Needham, Denning, etc.) I wonder why the first message where the identities of the client and remote are not encrypted. In case not encrypted I ...
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1answer
43 views

Do we need to same PGP version for decryption [closed]

Requirement: In our company Location A uses PGP encryption and sending data over internet. In Location B, we have to decrypt the file. Question is what do we require in Location B Do we need to ...
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1answer
58 views

Retrieve anonymous credentials

Background A registration process to acquire an anonymous, verified account goes like this: Registrant provides proof of individuality to a Registrar. Registrar verifies proof, ensures no prior ...
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1answer
61 views

P12 private key vs private key file : what is more secure?

The question is a bit tricky because they don't have the same purpose but : Do both kind of file face the same security issue concerning private key protection : password strenght ? (PBKDF2 as both ...
2
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3answers
137 views

Acceptably secure solution for users to log in with a short unique code only (no username)

I am creating a website whereby users are given an account by invitation only, and are sent a unique code by post. Users can then log in (at least the first time) by entering the code only. The goal ...
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0answers
23 views

How should an ISP approach Mutual Auth TLS for SMTP email? (Domain Auth Email)

I'm looking for an easy to deploy way to make email clients (MUAs) display my email messages in a secure manner. PGP and SMIME both do this today, but they are high touch, and require software or ...