Encryption is the process of transforming plaintext using a cipher to make it unreadable to anyone except those possessing the key.

learn more… | top users | synonyms

7
votes
1answer
469 views

OpenPGP Encryption / Decryption Process Using GnuPG

I want to know if my method of encryption can ensure the security of my data if my database was hacked as well as the authenticity of the data I am decrypting. I am using GnuPG's implementation of the ...
9
votes
5answers
11k views

What does “key with length of x bits” mean?

I'd like to know what it means to say "the cryptosystem C uses keys with a length of x bits". I do not understand what the bits length means... doesn't it depend on the encoding? The same word encodes ...
6
votes
1answer
1k views

Select a TripleDES key so that it effectively behaves as regular DES

I'm working with a smartcard (DESFire) that supports both TripleDES and DES. In the specs it is stated that both modes of operation use 16 bytes keys. When the first 8 bytes in the key are identical ...
14
votes
6answers
1k views

How can the impact of cold boot attacks be minimized?

Short of powering down and maintaining physical security for sufficient time, what are effective strategies for keeping keys from being disclosed by cold-boot attacks, and can anything be done without ...
3
votes
3answers
3k views

RSA 4096 with AES 256 Encryption Process Using PyCrypto

I have the following process for encrypting and decrypting data in a python script using the PyCrypto module: Encryption - Server A AES 256 shared key is generated Associated IV is generated Data ...
12
votes
2answers
599 views

Is it possible to have a key for encryption, that cannot be used for decryption?

For example, a server might have some encrypted logs or storage or whatnot, that would only be used for reference later. This way even if the server is hacked, everything is still OK until the hacker ...
5
votes
1answer
3k views

Protect access to an SD card

How can I protect access to an SD card, so that only authorized users can read or modify the content of the SD card. Currently everybody who has physical access to the SD card can read or modify ...
13
votes
11answers
1k views

For users that does not use PGP, what would be the other channel to securely send them a document?

I would like to send a document that is confidential to users that have no clue what PGP is (so no point in teaching them how to install it etc...) via email. The real question is how to do that? ...
4
votes
2answers
284 views

When unlocking an encrypted drive, how does the unlocking program know it was successful?

This is very similar question to: If someone breaks encryption, how do they know they're successful? Basically, the answers to that question is that an attacker doesn't know when decryption was ...
2
votes
1answer
725 views

What browsers support encryption or decryption using local certificates, or smartcard readers?

I am working on a cloud-based solution and I would like to encrypt / decrypt the data locally using either a SmartCard or local Machine certificate. I'm hoping to do this in Javascript, but may ...
11
votes
5answers
3k views

What is the benefit with using encrypted RAM Memory?

I sometimes hear that encryption is used for the RAM Memory, but I don't really understand why this is needed. Why is RAM Memory needed to be encrypted? and is this done by the hardware, the ...
11
votes
1answer
1k views

Native rsync protocol security

Is the native rsync protocol (port 873) secure? Does it encrypt data or credentials? I'm planning on using rsync to store encrypted files in the cloud, I'm wondering whatever the password is ...
14
votes
3answers
3k views

Computationally simple, lightweight replacement for SSL/TLS

Target hardware is a rather low-powered MCU (ARM Cortex-M3 @72MHz, with just about 64KB SRAM and 256KB flash), so walking the thin line here. My board does have ethernet, and I will eventually get ...
1
vote
2answers
1k views

Thoughts on Tiny Encryption Algorithm (TEA, anyone)?

I'm planning to implement Tiny Encryption Algorithm and exchange data between two PHP sites. Specifically, using the code presented at PHP-einfach.de Does anyone have any experiences / thoughts / ...
4
votes
3answers
442 views

It is safe to buy a domain if I get this message in Firefox?

Greetings, I want to buy a domain name from a big registar(well known on the internet) but when I go to checkout I see that my link is going from full encrypted to “Connection Partially Encrypted” ...
7
votes
3answers
740 views

It is possible that brute force attempts are successful before the worst case, correct?

When I read about a password being secure and stating that it would take X amount of week, years, etc. isn't that referring to the worst case? What happens if the brute force method is successul in ...
26
votes
2answers
1k views

Are URLs viewed during HTTPS transactions to one or more websites from a single IP distinguishable?

For example, say the following are HTTPS URLs to two websites by one IP over 5 mins: "A.com/1", "A.com/2", "A.com/3", "B.com/1", "B.com/2". Would monitoring of packets reveal: nothing, reveal only ...
7
votes
2answers
4k views

Simple way to encrypt files on Linux and decrypt on Windows?

We are in need of an encryption process for backups of very valuable data. This data will be stored on a distributed filesystem, so even with permissions set right, its not out of reach that this data ...
6
votes
2answers
740 views

Do Flash memory (SSD) architecture impacts encryption techniques?

I'm working on encryption techniques on SSD's and my question is: does the erase before write architecture of SSD's has anything to do with the encryption technique? What are the problems I might ...
12
votes
4answers
527 views

Encrypting data by parts vs encrypting the whole data

Suppose I have a file with records, and I have two options to encrypt it: encrypt the file as a whole encrypt each record separately and store them together. Which way is generally preferable and ...
5
votes
4answers
492 views

Possibility of undetectable encryption system

I am not sure if it is pre-mature to ask such a question. The question is largely inspired by pondering over the question and discussions in the following link (In his answer, @Dad also raises ...
12
votes
3answers
2k views

Question about dictionary attacks on GnuPG symmetric encryption

They say algorithms like AES can't practically be broken given a long enough key length (> 128 bits). If I use GnuPG to encrypt a file using AES: gpg -c --cipher-algo AES secretfile it asks me for a ...
2
votes
2answers
216 views

Is random data inserted into an encrypted stream easy to retrieve?

Given that I have two pieces of data: A large piece of encrypted data. A small, fixed-size piece of random data. I want to be able to transmit both pieces of data together, but I don't want the ...
3
votes
2answers
185 views

Encrypting a fixed format message?

I'm planning to send across TWO pieces of information over the internet from machine A A site identifier which will be like: $SiteName = "EXAMPLE" (in plaintext) Encoded text which will be like: ...
6
votes
2answers
2k views

Export laws on the cloud (key size)

Do the U.S. export laws around AES-256 apply to applications hosted in the cloud?
8
votes
2answers
2k views

3DES vs DES for VPN connections

I'm trying to get Android 2.1 phones to connect to our corporate VPN, but it would appear they only support DES rather than 3DES for encryption. Is it safe to use DES, am I going to get hacked if I ...
6
votes
2answers
522 views

How can I authenticate a client connection in a secure way?

Let's say I have a server listening on port 1234. I have some client software that needs to be able to connect to this port. But I want to prevent malicious users from bypassing the client software ...
4
votes
2answers
773 views

Which is the easiest secure file transport protocol to implement (SFTP, FTPS, HTTPS, FTP over SSH, FTP over IPsec)

I have to select a secure file transfer protocol, to be implemented in a pre-boot system. I have access to libraries with the basic network functionalities (IP, TCP, UDP, etc...). I might also have ...
6
votes
2answers
721 views

How do I use Skein's Stream Cipher?

I understand the NIST hash function competition candidate Skein comes with a built-in block cipher, Threefish, that is turned into a stream cipher by using Unique Block Iteration chaining (is that ...
5
votes
3answers
11k views

Which type of encryption algorithms android supports, and which would be better?

I read this documentation, and I have written an algo to encrypt and decrypt a string. But I don't know how many types of algorithms android supports. Regarding DES and AES (As wiki documentation) ...
11
votes
5answers
610 views

Security of using passwords or even passphrases to encrypt files

Is it ever appropriate to use real-world passwords to encrypt files to be sent via unsecure means. By real world, I mean a password that is memorable and memorisable by a mere person? I am implying ...
12
votes
5answers
4k views

Use RSA keypair for PGP encryption and decryption

Is there a way that I can use a RSA keypair with PGP? What I mean is that I have 2048 length keypair and i want to use that to encrypt and decrypt data. But all I have found is that the PGP uses some ...
8
votes
3answers
1k views

Security implications of storing the password hash along an encrypted AES key

I am using the PKCS#5 standard to generate a key using a random and unique salt and the user's password in input. Consider this key as the "encryption" key. The "encryption" key is used to encrypt a ...
14
votes
6answers
598 views

Primary Key as Salt?

Is it okay to use the primary key as the salt in a Users table? The only disadvantage that I can see is if the PK changes (unlikely), then the passwords break. What are your thoughts?
5
votes
1answer
612 views

Should I include a random padding in every HTTPS request and response?

According to the following paper, it is possible to decrypt HTTPS traffic by inspecting AJAX calls and using the size parameter as a cryptographic oracle. Should I be sending a variable length ...
4
votes
1answer
263 views

Can wildcard certificates hide/obscure the hostname in a TLS connection?

I'm trying to increase security for my cloud-based / multi-tenant environment. I'm considering having clients access an obscure URL such as GUID.myCloud.com. I will then respond to that guid-based ...
4
votes
5answers
15k views

Is there a simple example of an Asymmetric encryption/decryption routine?

I can understand Java, Perl and JavaScript code very well. The rest, I have not studied, but I guess I could figure out how to read/translate. I would like to know what the simplest of Asymmetric ...
5
votes
1answer
764 views

Clarification needed for NIST's whitepaper “Recommendation for Password-Based Key Derivation”

What are some sample use-cases the NIST is supporting in this policy / whitepaper regarding PBKDF2? This Recommendation specifies a family of password-based key derivation functions (PBKDFs) ...
10
votes
5answers
2k views

Storing private asymmetric key in application binary?

I would like to give a daemon-style process (i.e. no user interaction) access to a shared secret key so that it can access a shared, encrypted data file. User applications accessing the same encrypted ...
7
votes
2answers
733 views

Encryption Algorithms with an error code for wrong password

I am looking for an encryption algorithm that would allow me to know if the password supplied is the correct one or not. This question can be considered as a follow-up for Q. In particular the answer ...
4
votes
3answers
389 views

Are there any serious problems with this technique for generating symmetric keys?

I'm using a technique borrowed out of a book by Bruce Schneier and Niels Ferguson called Practical Cryptography. Basically, it boils down to this: Bob does this: pubk_A = Alice's public key ...
9
votes
3answers
1k views

Is TDEA (TripleDES) invulnerable to the weak keys of DES?

The key space of DES includes some keys that are weak, which results in a ciphertext that is extra vulnerable to cryptanalysis. Is TDEA (also known as TripleDES) invulnerable to those weak keys? Or, ...
1
vote
2answers
982 views

How effective have statistical methods been at breaking encryption?

If we look at how statistical engines run on-line translators, and how they are built, we see that they look at a new language and run a statistical model over it searching for what's probably the ...
1
vote
0answers
272 views

Server side data de-duplication + client-side encryption with private key. Possible with “convergent encryption”? [duplicate]

Possible Duplicate: Online backup : how could encryption and de-duplication be compatible? I just saw an article on Techcrunch wherein a startup company was describing their new cloud ...
5
votes
3answers
1k views

Is it safe to use different derived keys but from the same passphrase for AES CBC encryption followed by HMAC SHA256 hashing?

I am working on a cross platform (JS/iOS/Android) list manager application that persists data through a REST API and I want to ensure that any textual data is properly encrypted on the client side so ...
13
votes
4answers
1k views

Is Steganography considered encryption and subject to USA export restrictions?

I have written an application for Apple's iOS which embeds messages in JPEG files using steganography (see http://en.wikipedia.org/wiki/Steganography). For the purposes of this question lets assume ...
4
votes
2answers
585 views

Protecting data on a laptop with linux

I'd like to keep some private data (photos, notes, ...) and my browsing data hidden. The rest is not so important. Most of the time I just put the laptop to sleep and don't shut it down often, making ...
12
votes
2answers
4k views

Smartphone / GSM Sniffer

This question would be in the category of SmartPhone Sniffers. So we have sniffers that can show the packets that are being sent across a wired or wireless (802.11) network. I am just performing a ...
1
vote
1answer
559 views

Android application level encryption cracking

We come across Android applications which use the custom encryption. When we proxy the Android phone or emulator, the proxy captures traffic which is unreadable. Is there a known technique to read ...
13
votes
3answers
1k views

What's the mathematical model behind the security claims of symmetric ciphers and digest algorithms?

Why can SHA-1 be considered a secure hash function? That's something I still wonder about. I understand the concepts of why modern asymmetric algorithms are deemed to be secure. They are founded on ...