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

14
votes
3answers
750 views

Can a nation-state adversary perform a MITM attack by compelling a CA to issue them with fake certs?

As I understand it, with any encryption system based on a trust chain / CAs (eg SSL, TLS, S/MIME), it would be possible for a nation-state adversary (such as the NSA) to compel the CA to issue them ...
14
votes
2answers
1k views

Flaw in encryption through pseudorandom number stream (from gpg documentation)

I was reading PGP docs and came upon a part written by Phil Zimmermann (PGP's creator) that piqued my curiosity: When I was in college in the early 70s, I devised what I believed was a brilliant ...
14
votes
2answers
2k views

How does non-ephemeral Diffie-Hellman key exchange become compromised in SSL when the RSA private key is leaked?

From my understanding, one of the major reasons we recommend Diffie-Hellman Ephemeral (e.g. DHE or ECDHE) over non-ephemeral DH, for SSL / TLS, is that compromise of the RSA private key (i.e. private ...
13
votes
7answers
6k views

What are the realistic, and most secure crypto for Symmetric, Asymmetric, Hash, Message Authentication Code ciphers?

I'm interested in updating this two pronged question for 2011: What cryptology is most appropriate for low-powered devices (such as a cellphone), and yet still effective? What cryptology is most ...
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? ...
13
votes
4answers
5k views

What are you doing when you move your mouse randomly during a truecrypt volume creation?

Is that called a 'round' every time you move your mouse when creating a new volume? I'm talking about the screen with the random numbers during the volume creation process. What is the purpose of ...
13
votes
3answers
843 views

How secure is aSSL (javascript)? Does it effectively mimic SSL?

Some of you may be familiar with the aSSL project, which uses AJAX/PHP to mimic the SSL protocol. It uses RSA 512 or 1024 for the keys, and AES for the actual data. It looks impressive to me in ...
13
votes
7answers
967 views

Has cryptography reached the development level where social engineering is the only reliable method of attack?

Note that for the purpose of this question, "social engineering" means extracting information from humans, be your methods compliant with Geneva Conventions or not. Simply put: Do cryptographic ...
13
votes
5answers
1k views

How should passwords be stored if they must be recoverable?

By "encrypting" passwords you are violating CWE-257: Storing Passwords in a Recoverable Format. But this is exactly what the French government wants. They want to be able to obtain the passwords of ...
13
votes
2answers
759 views

Does the haystack theory work

The haystack theory is the recommendation to put repeated characters in your password in order to make it harder for brute force to reveal. Does this have any mathematical basis? Or is it snake oil?
13
votes
9answers
7k 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 ...
13
votes
3answers
2k 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 ...
13
votes
3answers
2k views

Is amazon S3 secure enough to hold personal documents?

I have a client who is looking to hold personal information such as Driving Licences and Insurance documents in order to verify if a user of the site is who they say they are and lives where they say ...
13
votes
5answers
5k views

SQL field level encryption, how safe is it?

I am considering encrypting my database and/or encrypting only certain columns in a few tables. Is it worth the time? I mean, how much of a burden would it be on someone if they were to get a hold of ...
13
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 ...
13
votes
2answers
3k views

What's wrong with storing private keys in the cloud?

I know this sounds like a dumb question, but whats wrong with it? Assuming that all private data is encrypted (by the client) using PBE AES256, then is this scheme more vulerable than storing keys on ...
13
votes
2answers
3k views

What should I know before configuring Perfect Forward Secrecy?

PFS has gained attention in our audit department because of its innate ability to limit our exposure if someone steals our private key. What pitfalls or common mistakes should I be aware of before ...
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 ...
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 ...
13
votes
1answer
1k views

How would I implement “Broadcast Encryption”?

I have a stream that I want to encrypt for broadcast to 10,000 subscribers. I know I should encrypt this data using a symmetric key; and also intend that this symmetric key will be rotated every 30 ...
13
votes
2answers
749 views

Storing sensitive information securely

I know there have been a few questions about this already, but I just wanted to know if anyone can take a look at my design plans to see if there are any gaping security holes. I am in the process of ...
13
votes
3answers
4k views

How to encrypt database connection credentials on a web server?

OWASP advise against storing DB credentials in plain text: https://www.owasp.org/index.php/Password_in_Configuration_File However, they don't provide suggestions of how to encrypt the DB access ...
12
votes
8answers
3k views

Is Steganography a safe method to store secret data?

I want to put some parts of my secret data into specific file with Steganography method. Is this method as safe as other encryption methods like RSA or SHA?
12
votes
2answers
971 views

Why use 256-bit symmetric encryption in TLS when 2048-bit RSA doesn't even offer 128-bit strength?

I've noticed that websites start to use 256-bit symmetric encryption, but often still end up using 2048-bit RSA keys. http://www.keylength.com/en/3/ The link above displays the ECRYPT II ...
12
votes
2answers
502 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 ...
12
votes
5answers
4k views

How can I decrypt data with Java, without hard-coding the key?

I hope this is not a chicken-egg problem or reinventing the wheel but here goes. I have a Java application that needs to access a password protected file (actually during the application startup). The ...
12
votes
4answers
454 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 ...
12
votes
5answers
3k 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 ...
12
votes
2answers
2k views

Does AES-192 provide better encryption than AES-256?

this wikipedia article describing AES says: Related-key attacks can break AES-192 and AES-256 with complexities 2^176 and 2^99.5, respectively. Does this mean that AES-256 is actually a weaker ...
12
votes
5answers
933 views

Is there a digital “safety deposit box” equivalent?

Digital safety deposit boxes: do they exist? if yes, are (any|they) trustworthy? There are many bricks and mortar financial institutions where one can rent a locked box in a locked room and be ...
12
votes
2answers
569 views

Is a large number of RSA-encrypted files a vulnerability?

Would having a large number (10^4) of RSA encrypted files make it easier for an attacker to find my private RSA key? Update: These files would be available to the attacker, and perhaps the content of ...
12
votes
4answers
3k 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 / ...
12
votes
1answer
327 views

What are the problems with encrypted but unsigned data?

In another question's answer, D.W. wrote: Make sure there is authenticity protection for the encrypted data (e.g., encrypt and then sign/MAC): you will need both confidentiality and authenticity ...
12
votes
3answers
2k views

When using AES and CBC, can the IV be a hash of the plaintext?

[Originally on programmers.stackexchange.com with title: Can you encrypt with AES+CBC and search the encrypted data] Basically, I'm going to go with Advanced Encryption Standard with either ...
12
votes
4answers
1k views

Encrypting IP addresses in a MySQL database

I'd like to encrypt IP addresses in my MySQL database, with the following constraints: Does not need to be resistant to attackers that can execute queries. Must be resistant to attackers that have ...
12
votes
2answers
3k 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 ...
12
votes
2answers
2k views

Encryption strategies for multi users access in production systems

I am pretty unknown to encryption strategies in production environments. So my concern is to find a solution how to strongly encrypt data, but make it available to multiple users with different keys. ...
12
votes
2answers
4k views

Encrypting with Mongo

How can I achieve the following goals? All compute and storage to be located in the cloud. Encryption in transit of all data between web nodes and db nodes running MongoDB. How to set up tunnels? ...
12
votes
2answers
821 views

Protection of Keys/Passwords on Virtual Hardware (XEN, KVM, VMWare, etc.)

Is there any reasonable way to secure data on virtual hardware? What I mean by "virtual hardware" is the various hosted systems that one can rent from various online hosters, that run on top of XEN, ...
12
votes
3answers
2k views

How are mobile telephony networks like LTE and HSPA encrypted?

How are mobile telephony networks like LTE (4G) and HSPA (3G) encrypted? between what parts is the communication encrypted? who has access to the keys? is symmetric or asymmetric encryption used? is ...
11
votes
2answers
19k views

What are the differences between MD5, SHA and RSA?

MD5 tools output hexadecimal values. In the same manner, do SHA and RSA together produce a hexadecimal (or any other) output? What are the differences between the MD5, SHA and RSA algorithms?
11
votes
9answers
13k views

Techniques for Writing Encryption Algorithms (Exclusively For Personal Use)

I'd like to preface this question by stating that I fully understand the dangers of writing your own encryption algorithms, and I would never, ever, use homemade encryption to secure the data of ...
11
votes
6answers
2k views

Identity-Based Encryption - how secure is it?

I was always taught never to invent my own crypto algorithm, and never to trust someone who has a proprietary algorithm. I'm looking at Voltage SecureMail, which uses IBE (identity-based encryption) ...
11
votes
4answers
1k views

Using computer random number generators to produce keys, it is secure?

Does generating an encryption key using the random number generator on one's computer present a security risk? If so how might that risk be mitigated, specifically when generating RSA key pairs in ...
11
votes
4answers
4k views

Does symmetric encryption provide data integrity?

Let's say I have one server that encrypts a file with a symmetric key, e.g. AES-CBC, and sends it to clients that decrypt it. Does that provide data integrity when decrypted? Or is it possible for ...
11
votes
4answers
1k views

What kinds of SSL certificates are usable for encryption?

I know that Verizon SSL certificates cost close to $600. There are couple of cheap alternatives, but I never really understood why Verizon does not offer such certificates. Look for RapidSSL at ...
11
votes
3answers
718 views

OpenSSL generates 1032bits when I request 1024bits

When I enter the command-line openssl dhparam -text 1024 the resulting safe-prime is 1032 bits instead of 1024 bits. It seems like the 1st byte is always 0. Why is this?
11
votes
3answers
4k views

Block chaining modes to avoid

Everyone knows that ECB operation mode with a block cipher should be avoided because of clear and obvious weaknesses. But little attention is given to comparison of the other modes in the context of ...
11
votes
5answers
2k 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
5answers
11k views

How secure is NTFS encryption?

How secure is the data in a encrypted NTFS folder on Windows (XP, 7)? (The encryption option under file|folder -> properties -> advanced -> encrypt.) If the user uses a decent password, can this ...