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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Should I use HMAC in this situation

I need to store a big message encrypted on a server. What I am about to do is: Encrypt the message with a AES key; (Authentication) Hash the message with SHA512 and encrypt the hash with RSA priv ...
3
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1answer
85 views

How to best to secure data over HTTPS

My aim is to have an (iOS) app in which the user would login, then on sucsessful login, gain access to additional information over an encrypted webservice (undecided). From research, I understanding ...
3
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1answer
107 views

Is it a good idea to do double AES encryption with 2 different keys, when one is held by the user and one stored on the server?

I'm building a web app. The app needs to keep certain data within the database very secure. Please assume for the moment that I don't have a HSM or Key-Management facility and can't afford to ...
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0answers
43 views

SSL Asymmetric encryption newbie [duplicate]

I am relatively new to the world of cryptography and was wanting to develop a webpage which allows credit card payments. Thus, I looked into the digicert ssl service, hoping that it could do what I ...
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2answers
117 views

Does client side encryption really add security?

A lot of password managers seems to promote client-side encryption as a key feature of their service. For example : LastPass, Firefox Sync, PasswordBox, etc... They all say something like Even we ...
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0answers
19 views

Infer encoding mechanism from n-grams distance

I have a series of obfuscated strings which across the set of strings have regions of high variance and regions of low variance (implying some encoding mechanism as opposed to an encryption procedure ...
4
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2answers
3k views

Is your PGP passphrase used to decrypt an encrypted private key, or needed in conjunction with the private key to decrypt the message?

If the former, then if the private key can be used to digitally sign messages, why doesn't your client offer to encrypt this highly sensitive piece of data? If the latter, then if someone had access ...
2
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1answer
94 views

How does Putty derive the encryption key in its .ppk format?

I have been doing some reading on the mechanics of managing RSA key pairs, during which I learned that OpenSSL by default derives the encryption key by using MD5 on the passphrase (bad!) without any ...
2
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2answers
84 views

TLS reliance on System Time

I'm interested to know if there is any reliance on system time (as defined by Linux or windows) when initiating a secure handshake. I'm aware that TCP typically uses a random number (RFC 1323) to ...
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1answer
62 views

Exchange of encrypted files through a server

I have a thing to do, that basically bases on a server that is honest but curious. Therefore I want the server to have the public key for encryption and it will encrypt files during the process of ...
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2answers
52 views

2 way encryption of a string into numerical string using random number

I have a random number like 0.323978544752212. I want to encrypt a string using this random number into to numerical string i.e. final string is like ...
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4answers
178 views

Is 3DES outdated for message authentication code computing?

I am working in IT department of a bank, currently we use 3DES to compute MAC of packet, is that safe enough using 3DES? Should we use any other more modern algorithm?
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63 views

Encryption algorithm keySize restriction in JSSE 7

I have an application which uses SSL (JSSE Implementation). Currently from my client side, the "Client Hello" message suggests a list of cipher suites that consists of both 128 & 256 bits key ...
2
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2answers
293 views

Why doesn't Bitlocker mix the password with stored key?

Bitlocker doesn't support USB key + PIN (password). The reasoning was "the password is too weak to provide additional security". Isn't that flawed? With a USB key and password, I've got some level of ...
2
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2answers
731 views

Can Poodle be fixed in SSLv3 or will it go the way of TLS compression?

Is TLS_FALLBACK_SCSV going to be the fix for servers that wish to keep SSLv3 enabled? If not what actions are being taken, if any, that address the vulnerability besides disabling SSLv3?
3
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4answers
173 views

How do I encrypt external drive with Password which is compatible with both Linux and Windows? [closed]

I wanted to encrypt my external drive with password, which is compatible in both Linux and Windows. Truecrypt is an option. But the development of it is stopped few months back. I came across ...
0
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1answer
67 views

Understanding Digital Signature

I have just learned Digital Signature and am trying to ensure that I have got my understanding of Digital Signature on the correct track. Assume Alice wants to send a message (M) to Bob where the ...
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2answers
164 views

Fake phone call

I have a problem, getting call from known numbers and when he lifts it, no one is speaking from other side! Well, the awkward part is, the call is from known numbers only, but if I ask the person ...
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2answers
75 views

What's the benefit of hybrid cryptosystem vs asymmetric for small data blocks?

It's a common belief hybrid cryptosystems are better than asymmetric only. Is that allways like that? What's the benefit of using symmetric and asymmetric encryption for small data blocks (< 100 ...
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3answers
37 views

Do passphrases need to be run through PBKDF2? Almost impossible to brute force?

Passphrases normally contain more data then passwords and can provide more entropy. It seems like it would still be hard to brute force a passphrase w/o using PBKDF2, assuming a user didn't select a ...
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1answer
38 views

Can the aproximated date on which a given Encryption Algorithm will become prone to brute force be predicted?

I have a very elementary understanding about encryption so this question may have false assumptions, Lets take an encryption algorithm that is impractical to break through bruteforce with today's ...
1
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1answer
55 views

Decrypt signature file based on plaintext

I have 2 text files used by an application. One is a very large "schema" array (approaching 100,000 lines, JSON format). The other is a .txt.sig file generated somehow from the contents of the schema ...
0
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1answer
87 views

How will Gmail be able to detect SPAM and display ads when emails are encrypted end-to-end?

Context Google is making end-to-end encryption easier to use. SPAM How will they be able to perform SPAM detection when the email is transmitted and stored encryptedly? I suppose that if the SPAM ...
4
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3answers
308 views

Security Implications of using Base64 Encoding with Encryption

Are there any security implications of converting a byte-array encryption key into a Base64 string before use? I am creating a generic encryption helper for a project, and for the sake of consistency ...
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1answer
65 views

Is it safe to use private key encryption for lots of small blocks of data themselves?

I currently handle small JSONs of sensitive information which are guaranteed to be smaller than 100 bytes. You can encrypt up to ~500 bytes with a 4096 RSA key. Is it safe/secure to store these ...
2
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3answers
43 views

Encryption while logged in

If I'm using full disk encryption on my home computer, and it's online, are the hard drive contents encrypted when I'm logged in and using the machine (from the perspective of an online attacker - no ...
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1answer
46 views

Permutation based file secure

I have a thought. 1. Take a file. 2. Read number of bytes. If its less than 2048, padd it till 2048 3. Read each byte. And create a single file which contains the particular byte. Give a random name ...
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1answer
86 views

How negative are virtual machines (vms) to /dev/urandom?

I looked at the questions here and here. This then piqued my interest as I've recently been involved with looking into FIPS compliance, and in my vm environment /dev/urandom compliance testing ...
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1answer
85 views

Hardware Implementation of Encryption Algorithm

In the abstract of the AES-GCM RFC, the following passage is prominently included: [AES-GCM] can be efficiently implemented in hardware for speeds of 10 gigabits per second and above... Is the ...
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2answers
624 views

Security of several files all using same password/key (7zip, AES256)

I'm working on a simple secure mirror for potentially untrusted services like Dropbox, Owncloud and so on. (Current code may be seen here: http://www.codeduce.com/extra/secure_mercurial) Currently ...
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1answer
57 views

Is Lock-a-Folder a secure and reliable way to encrypt information?

What are the properties of Lock-a-folder? does it create plain-text temporary files anywhere? (e.g. ntfs artifacts, etc) does it allow running a program from the folder as if it was a normal folder? ...
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1answer
173 views

Can Cipher Suites defined in TLSv1.2 be negotiated by clients that only support TLSv1.0?

If my server has only the cipher suites enabled which are defined by TLSv1.2 does that force a client to also use TLSv1.2 or else not be able to connect or can the connection fallback to TLSv1.1 or ...
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2answers
51 views

PKI expired and renewed, do my correspondents have to do anything?

My PKI certificate (Digital ID for email from Symantec, issuer is "VeriSign Client External Certification Authority - G3") expired after 1 year and so I have renewed it. Do the people I correspond ...
3
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1answer
149 views

Hardware encrypted external HDDs

I'm planning to buy an external HDD with hardware encryption, namingly the WD My Passport Ultra 2TB. On the WD website the information about the encryption is sadly scarce so I'm asking here. How ...
3
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2answers
196 views

How do web email clients store my passwords from other providers?

The situation comes down to this: When I enter in hotmail, it retrieves my messages connecting to other providers: they could only do so by using my email and password. Since I had signed in a ...
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0answers
89 views

Database row level encryption scheme

I am wanting to secure some highly sensitive data in a database. This would mean that the data needs to be encrypted and remain secure for 100 years if it were to fall into adversary hands. I also ...
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2answers
3k views

Why is VeraCrypt more secure than TrueCrypt?

TrueCrypt retired with a mysterious "Using TrueCrypt is not secure as it may contain unfixed security issues" (source) Yesterday Slashdot reported VeraCrypt as a better replacement (source) since it ...
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1answer
462 views

Android support for TLS 1.1

Do anybody know from what version of Android did TLS 1.1 started to be supported directly by the OpenSSL version preinstalled in the system?
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4answers
744 views

Why the symmetric key is added to the message?

Yesterday in my class we learnt how to send a message from Alice to Bob with the achieved goals of confidentiality, integrity and authenticity. In order to have a better performance we use a hybrid ...
0
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0answers
30 views

Protect file with digital signature that can be verified using public key

Sorry if the answer is obvious, I am really new to this stuff. I need protect a file from changing using public-key cryptography. The file should look like this: Filecontent ...
2
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2answers
3k views

How do you bruteforce decrypt data if you don't know what you are looking for?

If I wanted to brute-force decrypt data, I would try decrypting it with a key and see if the decryption returned nonsense. If the decryption returned meaningful data (ex. something that a natural ...
1
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1answer
64 views

is this data encryption scheme viable?

My goal is to be able to encrypt the data so that no one would be able to make use of it if it was stolen. User data - the one that will be encrypted - can be any type of data Data encryption key - ...
2
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3answers
156 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 ...
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1answer
84 views

I want to encrypt content on USB or SD Card [closed]

I want to encrypt the content on a USB or SD card that can only be decrypted by an app installed on any device or TV. When the USB is not connected to that particular app, it should not be accessible. ...
1
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1answer
35 views

Difference between sshv1 and 1.5?

I've been searching for the answer to this but haven't had much luck. What is the difference between SSH version 1 and 1.5? Is 1.5 a release of 1? As in 1.2, 1.3, 1.4, 1.5? Are there any ...
4
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0answers
56 views

Linux, TRESOR and XTS

I want to switch from using LUKS for full disk encryption to TRESOR. TRESOR tries to prevent cold boot attacks by storing the encryption key in the CPU's registers. It uses the kernel's crypto API for ...
4
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2answers
156 views

Encrypt with private and decrypt with public

Above picture is captured from iOS Security overview at page 25. The path encrypt with public and decrypt with private makes sense. But the other path, encrypt with private and decrypt with public ...
0
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1answer
156 views

Hipaa Compliant Server

I have an instance in Amazon EC2 and need to be HIPAA compliant. I have two questions, Should I need to do a block level encryption of the database storage. Should I need to encrypt sensitive data ...
1
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1answer
135 views

Flawed understanding of SQL Server Transparent Data Encryption (TDE)

We host a database for one of our applications on Microsoft SQL Azure. One of our clients was dissatisfied with the fact that TDE is not supported on SQL Azure (and the database is otherwise not ...
3
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2answers
118 views

Would it be possible to create a zero knowledge social network?

I understand the concept behind a zero knowledge web application where only the user has access to their data. What about a social network where some circles of user have access to that data? Is it ...