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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How to make sure my data is secure even if someone gains physical access?

I've been reading up on how to secure my data if someone has gained physical access to the machine, e.g. stolen it. And that seems like a very hard thing to do, as indicated by a number of posts. It ...
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1answer
36 views

Detect if AES and hmac keys are invalid

I have a server which has a configured value of AES and HMAC key. The client also should have the same keys. When the client sends a request, the server interprets this request and reads the message. ...
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1answer
42 views

Create Public Key using OpenSSL instead of PuTTYgen for PKCS#8

I'm trying to create a public key pair for ssh-rsa authentication. If I'm using puttygen.exe, the "OpenSSH authorized_keys file" string looks like this: "ssh-rsa AAAAB3 ... 6yIK9Nbw== ...
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3answers
553 views

Is AES 256 secure enough for putting Backups to AWS or Dropbox?

How long would it take with current hardware to hack an Disk Image which was encrypted with AES 256? I ask because i want to backup personal files (contracts, tax-things, code, keys, private ...
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1answer
50 views

What is the “segment size” when using Cipher FeedBack (CFB) chaining mode?

When using CFB chaining mode with AES, I see instructions that the "plaintext length (in bytes) must be a multiple of segment_size/8" (also mentioned here). What does that mean?
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1answer
94 views

Decrypt a file by knowing the original content [duplicate]

We had some ransomware get into our system a couple of weeks ago, and it has encrypted a large amount of our files. I am wondering, is it possible to figure out an encryption key if I know the ...
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0answers
45 views

Are there any “best practice” encryption tools for these classifications? [closed]

I appreciate there are different requirements when it comes to protecting data – however to try and get a better feel of the security landscape.... ...when considering the CIA triad: ...
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1answer
37 views

Sharing Derived Unique Key Per Transaction (DUKPT) Base Derivation Key (BDK) with a partner

Assumptions: We have devices out in the field injected with keys derived from our one and only BDK. The devices encrypt data using the injected derived key. All our devices connect to our server ...
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1answer
63 views

Understanding Key Serial Numbers (KSN) in Derived Unique Key Per Transaction (DUKPT)

I have a number of questions regarding Key Serial Numbers (KSNs) in DUKPT: KSNs are 8 - 10 bytes long. Older implementation are 8 bytes whereas newer ones are 10 bytes. Do I risk being incompatible ...
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1answer
199 views

Prevent CryptoLocker on Server

A quick question, which may have a not-so-quick answer - Are there any ways to prevent files associated with CryptoLocker, to be propagated to a data server, by means of a back up? We use Cobian as ...
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0answers
54 views

Vault Secret server best practices

Recently Hashicorp released a secret management solution called Vault. Which is a free and open source general secret storage, acting as a vault for passwords, encryption keys, and hash salts. I am ...
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0answers
18 views

Are all homomorphic encryption schemes not CCA secure? [migrated]

Homomorphic encryption is hyped by computer sciences because it offers great potentials. For example you can perform cloud based calculation while nobody gets to know you data. I am wondering if ...
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8answers
5k views

How does malicious software encrypt victims' files?

Encrypting a file to me is akin to dealing with a very long string, feeding it into the hashing or encryption function to get another long encrypted string (or a hash in the case of hashing). This ...
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0answers
40 views

Is it secure to use pbkdf2 for both password hashing and key generation

I'm writing a password manager, right now for each individual site, I already used master password + random salt with PBKDF2 to generate encryption key to encrypt its password (each site has its own ...
2
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1answer
421 views

Protecting decryption key on server

What is the most suitable way to encrypt and decrypt sensitive data on a public cloud server disk without storing the decryption key on the server in plaintext? REQUIREMENTS In our SaaS web/mobile ...
2
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1answer
67 views

How to implement encrytion/decryption system using IV between mobile app and web service

In my app we are going to send encrypted data to the web service. I am using the following code to encrypt and decrypt the data - public class DecEn { private static final String password = ...
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1answer
45 views

Are OpenSSH vs OpenSSL public key format names mismatched?

I generated a key pair vis OpenSSH and later wanted to generate PEM encoded public key. I noticed that generated public key differs when generated by OpenSSH vs OpenSSL when using same format name ...
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2answers
46 views

Requirements Placed on a User of a FIPS 140-2 Validated System

Per customer requirements, I am working with a FIPS 140-2 validated network switch that is actually running in FIPS mode. This guarantees that any cryptographic operations the device performs will be ...
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1answer
128 views

Are there any alternatives to EFS for transparently encrypting the contents of a folder in Windows?

EFS is not an option for me because I'm using Windows 7 Home Premium. I am looking for folder encryption, not drive encryption.
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2answers
165 views

What type of encoding do .pem files use to store the key?

What encoding is the modulus in RSA cryptography stored as in a .pem file? Is it something similar to base64 of the modulus? I can retrieve the modulus using the following: openssl rsa -in ...
2
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1answer
105 views

Where to store hashes, salts, keys in Desktop Applications

I am trying to figure out where or how i should store application secrets and keys inside a desktop application. For example a facebook app key or dropbox key and secret. So I've read that i should ...
2
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2answers
313 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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2answers
25k views

Is it possible to decrypt a satellite TV signal without using a smart card?

And if it is possible, why has it been decided to keep using a smart card for this task? I will be grateful if you can provide some practical examples on how to bypass the use of a smart card (if ...
2
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1answer
97 views

Is it insecure to provide a hash of an AES password?

I have made some software that encrypts and decrypts files using AES. I was wondering if it is safe to write a hash of the password to the file so that the program can check if a password is correct. ...
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3answers
74 views

Best method for securing text based messages [closed]

If I wanted to use a device for the sole purpose of sending and receiving text based messages, could it be done so that the messages from A to B are as secure as possible, the information is easily ...
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0answers
21 views

Reformatting drive from a GUID partition to an MBR partition [migrated]

I understand that Truecrypt is not compatible with an GUID partition but that is the limit of my knowledge. I am currently using a system that has a GUID partition but doesn't have bitlocker ...
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1answer
75 views

Why am I getting the message that Security Stack Exchange is only partially encrypted? [closed]

I realize that this is an information website but it does concern me a bit that I'm getting the message that this website does not supply ownership information. Does this mean that my posts can be ...
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1answer
49 views

Is it true that breaking into the https padlock settings on a web page is easy to do? [closed]

I found some posts on this forum that explained that https settings are possible to crack. see here. Why is it possible to sniff an HTTPS / SSL request? And here is another post that mentions ...
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2answers
149 views

Is storing encrypted data in a database futile?

The way I see it: there are two ways to encrypt data for a web app. 1) Store a single encryption key on the server, and use it to encrypt / decrypt data at runtime. The obvious issue here is that if ...
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3answers
5k views

Tool or Process to check for AES-NI support on processor?

In another question, Thomas' answer mentioned the AES-NI instruction set, which piqued my curiosity. Is there a tool or process available out there to check whether the instruction set is available ...
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2answers
88 views

Could a compromised root CA impersonate any SSL certificate?

My question is about MITM attacks against https and how those would appear to the end user. Suppose a trusted root CA were compromised / coerced into producing fraudulent SSL certificates. What would ...
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2answers
15k views

Do VPNs provide sufficient protection over public wireless networks?

I know that VPNs are the standard way to secure communication between a remote user and their primary network, but I've never felt entirely comfortable relying on them when using an open wireless ...
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1answer
186 views

Publicly Available API + Sensitive ID/Key Transmission Over HTTP

I've run into a predicament... I'm developing a mobile application that utilizes a server for various things. One portion is that it stores an id/key pair related to accessing and processing ...
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2answers
56 views

Methods to keep an autonomous log with high integrity

I'm writing a .NET desktop application that is used to send orders to a server via a REST API. To avoid leaking of our authentication token I have made it so that, when used for the first time, the ...
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1answer
129 views

Difference between fully homomorphic and semi-homomorphic encryption

What is the difference between fully homomorphic and semi-homomorphic encryption?
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1answer
891 views

Improving stateless REST API authentication token - or ditch it for database persistence?

I'm looking to implement stateless REST authentication into an API. I've been reading up on articles here, and have implemented an idea that works, but I was hoping to get some feedback on its ...
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1answer
46 views

Identify encryption algorithm for .enc files

I need to identify the encryption algorithm used to encrypt some files. I have the key, but I can't decrypt it using OpenSSL, because I don't know what algorithm was used to encrypt it. Is there any ...
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2answers
107 views

Is it feasible/possible to have encrypted data that looks unencrypted/innocuous?

i.e., could I send "Let's rob the store at 9 tonight" so that it is impossible to see what I'm saying, but it doesn't look like gibberish and obviously encrypted?
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1answer
48 views

Decrypting SSL traffic for Security Onion at or before the interface

I have Security Onion installed and doing full packet capture on my home network. I also have a firewall (pfSense) which does my routing. I have Security Onion sitting just behind my firewall and ...
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2answers
180 views

Is the same decryption key used for data on the server as locally with Lastpass?

Lastpass stores the password databases encrypted on the server. Does it give a database to anyone who asks? If no, then what authentication (i.e. password) is used? I use Lastpass on multiple devices ...
2
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3answers
129 views

Securely storing bank account details in database

I am developing a service that will involve the direct debit of customers' accounts on a routine (weekly, monthly, etc.) basis, and so I'll need to store their information (BSB/routing number and ...
2
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2answers
289 views

What is the problem with multiple encryption and how do you know if you have decrypted a cipher?

I have 2 questions that are somewhat related: 1. When you try and guess the key in a program (in a brute force way), how does the program know if it got it right and it had deciphered the message (I'm ...
3
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2answers
237 views

Multiple encrypted messages known to have matching (unknown) content

A recent discussion regarding ways to keep data secure through multiple iterations of a program's execution (with repeated read/write operations) raised a question regarding known-plaintext attacks ...
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1answer
38 views

Secure connection between two clients with shared secret

I am creating a system where there are multiple clients, each of which has a secure connection to a central server which could pass out shared secrets to each of them. I could be wrong, but I am ...
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1answer
58 views

Cloud-based IM protocols / services saving messages encrypted on server which is decryptable only by user? [closed]

I am looking for a cloud-based (i.e. not end-to-end) secure IM protocol or service. The first one comes to my mind is telegram. Here is a quote from telegram's privacy policy: Cloud Chats ...
1
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1answer
121 views

Any way to revoke old key pair?

There is a many-year-old 1024 DSA key in the public keyservers under my name. There is a 2048 ELG-E subkey for it. I didn't create these keys, they were created for me by a former employer without my ...
2
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1answer
83 views

UEFI and security implications for encryption

After my old PC kicked the bucket I now own my first UEFI board and I am already having trust issues. I utilized Truecrypt's system encryption for years now and really got used to it. My new board has ...
2
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2answers
436 views

No HTTPS on credit card entry form - can it be safe?

I was going to make a purchase on a website, but the page containing the credit card entry form is served via HTTP and not HTTPS. Is it definitely unsafe? The website advertises the use of ...
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1answer
25 views

Is it possible to assign different UIDs to subkeys for the purpose of having multiple identities?

Many people advocate generating new primary keys for each identity they wish to have. For example, creating one primary key and associated subkeys for workplace use, and a completely different ...
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2answers
353 views

Which default encryption does OpenSSL use?

If I create a private key via: openssl req -x509 -newkey rsa:2048 -out cert.crt then OpenSSL writes the private key to the file privkey.pem and if you do not provide the -nodes parameter it will ...