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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13
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6answers
5k views

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 / ...
2
votes
1answer
52 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 ...
16
votes
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
64 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 ...
2
votes
2answers
259 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 ...
19
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1answer
507 views

How to encrypt in PHP, properly?

How do I encrypt data in PHP, properly, using symmetric-key encryption? I have a message M and a secret S. I'm looking for a solution that uses cryptography properly without making any of the usual ...
0
votes
1answer
140 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 ...
14
votes
8answers
15k views

Encrypting files on Google Drive

It's my understanding files kept on Google Drive are not protected. I would like to have them encrypted so that to be able to view or modify them one must enter a password. I foresee a potential ...
1
vote
1answer
39 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 ...
240
votes
7answers
191k views

RSA vs. DSA for SSH authentication keys

When generating SSH authentication keys on a Unix/Linux system with ssh-keygen, you're given the choice of creating a RSA or DSA key pair (using -t type). What is the difference between RSA and DSA ...
1
vote
1answer
60 views

Message and Key Security

I'm reading Post-Quantum Cryptography, and in the page 106 in the beginning of the Section 3 it says: In this section we consider the message security (opposed to key security) of code-based ...
1
vote
1answer
93 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 ...
2
votes
0answers
58 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 ...
0
votes
0answers
26 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.
0
votes
0answers
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 ...
0
votes
0answers
103 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 ...
1
vote
1answer
92 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 ...
0
votes
1answer
50 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 ...
1
vote
2answers
127 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 ...
0
votes
1answer
74 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. ...
2
votes
1answer
216 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 ...
17
votes
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 ...
1
vote
1answer
64 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 ...
2
votes
1answer
155 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 ...
1
vote
1answer
96 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 ...
0
votes
0answers
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 ...
1
vote
1answer
91 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 ...
1
vote
1answer
73 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 ...
4
votes
1answer
53 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 ...
17
votes
4answers
11k views

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 ...
2
votes
3answers
249 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 ...
0
votes
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 ...
1
vote
0answers
22 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
votes
1answer
112 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 ...
0
votes
1answer
71 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 ...
0
votes
0answers
365 views

Thunderbird password decryption from the signons.sqlite and keys3.db without using any third party tools

I understand from the Mozilla documentations that the passwords are stored in the following two files which are located at ~/.thunderbird/*.default location: ( I use Ubuntu 13.10) signons.sqlite ...
3
votes
2answers
318 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 ...
10
votes
5answers
2k views

Whenever an unhandled exception somehow makes it into production, is it safe, viable, etc. to print an encrypted stack trace to the end user?

Whenever an unhandled exception makes it into production somehow - whatever the reason - there's generally an option (especially with .NET programs) to print out a stack trace to the end user before ...
92
votes
9answers
54k views

Why can we still crack snapchat photos in 12 lines of Ruby?

Just came across this bit of ruby that can be used to decrypt snapchat photos taken out of the cache on a phone, apparently adapted from here. To my surprise, it worked no problem, considering the ...
61
votes
5answers
20k views

Is sending password to user email secure?

How secure is sending passwords through email to a user, since email isn't secured by HTTPS. What is the best way to secure it? Should i use encryption?
1
vote
1answer
217 views

How to secure my REST API once user authenticates with Google on mobile client?

In my application, I build REST APIs so that user can interact with my application server. Since I do not want to maintain User/Passwords, my iOS app authenticates client using Google. This all ...
1
vote
1answer
81 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 ...
-1
votes
1answer
45 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 ...
1
vote
1answer
60 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 ...
1
vote
0answers
30 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 ...
8
votes
2answers
6k views

The Pirate Bay - Secret Message?

The Pirate Bay will be relaunched as the timer indicates (see http://thepiratebay.se/) But on the bottom of the site is a "secret" message. What does this message mean? It's written in this image: ...
3
votes
1answer
122 views

How cryptographic hardware accelerator is secure?

I am using cryptographic hardware accelerator of am335x. As per documentation it unloads the cryptographic operations from the main CPU and hence increases the performance. But from the security point ...
2
votes
2answers
170 views

Storing lots of passwords that different levels of employees need access to

I am wondering what other people do for storing passwords. Our current model at my employer is fundamentally flawed in my opinion, so I am trying to see what other people do so I can select the best ...
3
votes
3answers
245 views

Calculate time taken to break AES key

A 256 bit AES key is required to be broken using the brute force method on a 2GHz computer. How long would it take to break the key in the best case and in the worst case situations? Assume that 1000 ...
4
votes
1answer
77 views

Do IVs need to be unpredictable?

I am encrypting a sequence of messages with AES/CTR. For each sequence, I generate a random initial IV, say IV(0). Define IV(i) = MD5(IV(i - 1)) for i = 1, ..., n. Then for each message m(i), I ...