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 that the public key has not been tampered with during transit?

I understand how public key infrastructure works. There is a private and public key, and someone may use the public key to encrypt data that can only be decrypted with the private key. However ...
0
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1answer
9 views

Securing FTP Creds in a Java Open Source API

I've written a basic Java API and source code must be released to a small community for the application to function correctly. The Java API helps developers track data for their running scripts and ...
12
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8answers
4k views

Would an encryption scheme that generates an extra key to be securely stored offsite be a safe backdoor?

Let me be clear first and foremost: I do not think installing a backdoor in security algorithms is a good idea. They undermine the trust in the software and in the company that provides the service. ...
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0answers
12 views

Whatsapp and Viber information security

Is it possible for my ISP or government to MITM communication that I have made via one of these 2 services(I live in not so developed country) ? I think I am reasonably safe from attacks at transport ...
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0answers
19 views

Use MDC to provide origin authentication for public key encryption?

Why can't we use an manipultation detection code (MDC) to provide origin authentication when using public-key encryption?
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0answers
22 views

File size influence on cipher speed (AES-GCM) with OpenSSL

NOTE: I don't really understand the math/logic behind the ciphering process, so this question may looks silly and/or obvious for some people... but in any case, could you point me to an article that ...
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0answers
64 views

How do I securely encrypt and store database encryption keys? [duplicate]

I have a database with encrypted information, and want to encrypt each entry with a different key. Then I want to store the encrypted keys in another database. I know I have to encrypt the keys before ...
-1
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0answers
34 views

What is elliptic curve cryptography and how does it work? [on hold]

What is elliptic curve cryptography and how does it work? Why is is usefull and how does the computer process it?
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2answers
16k views

Is it possible to use S/MIME in the web client of Gmail?

I could not find any options in the web interface of Gmail. All I could find was a Firefox plugin to use S/MIME with Gmail, but it seems to be outdated.
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0answers
48 views

Access encrypted partition from Linux and Windows [migrated]

Just to be clear, I'm a security noob. I have a Linux (openSUSE Leap 42.1) and Windows (10). I made the home partition of the Linux encrypted but now I cannot access it from Windows. The only ...
0
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1answer
152 views

How does the Signal Protocol, used by WhatAapp, work?

I want to understand the process of the Signal Protocol. I have google it, but I am unable to find any good article or tutorial. I want to understand the basic definition and functionality of the ...
2
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2answers
192 views

How to tell if an email is encrypted, or just corrupted?

Ran a recovery program (Kroll Ontrack) on a Windows 7 PC and recovered many, many emails. Almost all of them open in my Windows 10 mail client (and Thunderbird), except for a handful from this March. ...
0
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2answers
104 views

store passwords as one-way-hash, or just use it as an AES key?

I want to store some data so the only one who'll be able to access it is the user itself. Here is my idea: when user registers, his password will be hashed in SHA256 (so it'll fit as an AES key), and ...
2
votes
2answers
145 views

number of ciphertext-plaintext pairs needed in double encryption

So I know in single encryption you would simply require at least 1 pair of plaintext-ciphertext, to carry out an exhaustive key search; you continue trying different keys until one is found that ...
2
votes
1answer
142 views

access to mounted luks partition by non-root user

Recently I searched substitute for truecrypt and played a bit with cryptsetup. The steps I did: mkfs -t ext4 /dev/sdb1 sudo cryptsetup open --type luks /dev/sdb1 enc_vol sudo mount ...
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votes
2answers
93 views

Are the websites I visit using Windows Remote Desktop connection secure from my ISP?

Are the websites I visit using Windows Remote Desktop connection secure from my ISP? I am ok if my ISP knows the IP address of the remote desktop I am connecting with but will they also be able to ...
15
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4answers
80k views

CryptoWall 3 - how to prevent and how to decrypt?

My father's computer is now infected with CryptoWall 3, according to the link below. http://www.bleepingcomputer.com/virus-removal/cryptowall-ransomware-information#CryptoWall Is there a way to ...
0
votes
2answers
65 views

Asymmetric Encryption for Multiple Recipients?

Let's assume an arbitrary group of people who hold a key pair and who make their public key online accessible. Let X, A, B and C be arbitrary people from that group. Now X wants to encrypt a message ...
-1
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2answers
23 views

Security fails in private key and xor

I've implemented a very short program to encrypt a file, and send it on a remote server. First, I build a key based on a pass-phrase and a subset of prime numbers (the length of the key is defined by ...
0
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1answer
73 views

Handling user login using asymmetric cryptography

Is it possible to implement a login protocol with asymmetric cryptography instead of the hashed password method? For example, while creating an account, the client generates a private/public key pair ...
0
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2answers
50 views

What's the best place to hide long lived encryption keys

I am considering encryption options for a new Sybase project (internal facing only, sitting in our intranet) for a client that has a security policy that requires all sensitive data to use DB ...
0
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0answers
22 views

Would encrypting a signed JWT prove viable to secure claims payload?

I am working on a server-client web application, and as an authentication scheme, I am issuing base64 encoded json web tokens. Consider the following token... ...
1
vote
1answer
54 views

OpenSSL brute-force attacking and file size

I use OpenSSL with aes-256-cbc to encrypt a 30 GB tar file containing a recent backup of my hard drive. Now suppose somebody wants to run a brute-force attack on this file, trying out all possible ...
0
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1answer
26 views

Why is CBC-MAC insecure for variable length input?

Can anyone explain why CBC-MAC is not secure for variable length message? I read many books, but there are still some confusion. Like the highlighted parts in following pictures Slide 32: Slide ...
12
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1answer
1k views

MPPE-Send and Receive key derivation from MS-CHAPv2

I am trying to get the MS-MPPE-Send-key and MS-MPPE-Recv-key from the MS-CHAPv2 challenge material. I am able to follow the RFCs 2548 3078 and 3079 to the step of getting the GetNewKeyFromSHA() it is ...
2
votes
1answer
58 views

How well does FDE protect against disk firmware malware?

In early 2015 news broke that the NSA was installing firmware backdoors in many hard drives. I was wondering, if there was a BIOS and Hard Drive backdoor how well would full disk encryption protect ...
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2answers
182 views

encryption using two keys

The use case is analogous to accessing a safe box in a bank. There is a per-user key, unique for each user, either generated by the system or hashed from the user's password. And there is a ...
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2answers
88 views

Is encrypting a CRC with the plaintext ok?

We're using encrypt-then-mac for authenticated encryption, and recently added a CRC32 to the plaintext. Are there any security problems with using a non-authenticated hash mechanism (for example, ...
132
votes
5answers
123k views

Is Telegram secure?

There is a new WhatsApp-killer application called Telegram. They said that it's open source and that it has a more secure encryption. But they store all the messages in their servers and WhatsApp ...
0
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1answer
95 views

Is it possible to to encrypt multiple messages with multiple keys and get only one cipher?

I want to have cipher which when people decrypt it with their own key, get different meaningful messages. Is this possible at all?
0
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1answer
103 views

How secure is FaceTime by Apple

Apple says their messages and FaceTime calls are end-to-end encrypted and nobody can access them. As I'm unfamiliar with cryptology, I've found security white paper from Apple, where says: ...
2
votes
1answer
121 views

Offering a privacy scenario with PHP mcrypt library

first of all, sorry if my question is not clear, because English is not my first language. Anyway, let-me explain the concept I'm struggling to solve as the best solution. I have some guys, and they ...
2
votes
2answers
78 views

Is there a difference between getting encryption key versus encrypted data from server in terms of security

Suppose we have web and application servers and trying to encrypt credit card information for our financial web application. Communication between web and app servers are secured through SSL/TLS. Lets ...
1
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1answer
54 views

Making an encrypted SMS app (Android) [closed]

From my limited googling I've noticed that a lot of the mainstream encrypted messaging apps all are either (or a combination of!) closed-source, run through an uncontrolled third-party server, use a ...
0
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0answers
34 views

Is the QUIC protocol secure?

QUIC is a new protocol for video streaming, that can establish a secure connection in one round. It is used in Google's new Duo app for example. How does it work and is it secure (comparison with TCP ...
3
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0answers
76 views

Security of the shared secret key for a smart meter (Linky) [closed]

Reading the specs of a new electricity smart meter (called Linky in France), I was surprised about the chosen encryption method (128 bits symmetric key AES), based on a single secret key (called CCC ...
3
votes
1answer
107 views

DES Decryption followed by Encryption, will it produce the original text?

This is regarding DES. My question is, if a plain text is first decrypted (with the decryption algorithm) using Key K1 and then encrypted using same K1, would the result still be the original plain ...
3
votes
2answers
747 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 ...
1
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1answer
46 views

Key rotation benefits of a multi-key hierarchy

I think I have a decent grasp of the problems associated with key rotation, and as I'm working through them determining an approach for key management on an application I keep stumbling up against ...
4
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1answer
101 views

How to share an encryption key between different PHP applications?

I'm working with the php-encryption library to provide integration between two different applications. On one side, I have a corporative application that holds all data from users. This application ...
0
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1answer
44 views

Crypto++ RSA - Encrypt and sign with the same key pair

I have a program A which needs to send messages to several instances of program B (B1, B2, etc...). The messages must be encrypted, and also signed. Which means only Bn instances can decode, and they ...
1
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1answer
331 views

Corporation Best Practices for Encrypting Locally Stored Email Data

Since the recent Sony hacks took place, the attackers have published troves of data from users' email accounts. Some of this data is very detrimental to the company's image. I suspect that based on an ...
2
votes
1answer
73 views

Known vulnerabilities of GOST

Are there any known vulnerabilities in the GOST block cipher (GOST 28147-89)? Spcifically, I'm thinking about i.e. "master keys" which intentionally exist and are used i.e. by the Russian government. ...
0
votes
1answer
78 views

Windows security & data protection

I work for a hotel. The hotel stores a MySQL database online. This database only contains a Reference ID, number of nights and so on, but no private data. No names, no personal information on guests. ...
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votes
1answer
49 views
4
votes
1answer
101 views

How to protect TimeMachine backups from Ransomware?

According to Heise (German) Time Machine backups can be encrypted by Ransomware. Sorry I didn't find an English source, please use Google translate. KeRanger had an inactive module ...
3
votes
1answer
3k views

SIP Provider stores credentials, is it required for some SIP phones?

My SIP provider stores my SIP call time password as AES encrypted in stead of hashed. I understand that SIP authentication has the capability to NOT store the password, and in stead store a ...
1
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0answers
57 views

End-to-end encryption without user-keys interaction

Is it possible to have true end-to-end encryption even if the user is not involved in generating, selecting, transporting, or storing of the keys?
8
votes
3answers
906 views

How do poor-quality initialization vectors affect the security of CBC mode?

(If the consensus is that this question belongs on crypto, rather than here, please feel free to [tell me to] migrate it.) From what I have read (looking specifically at AES in Cipher Block Chaining ...
8
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3answers
1k views

Is it safe to sync private keys between iOS devices using iCloud?

My iOS app has to handle storing private keys for the user. Normally I would just use Keychain Services for this as I would a password, but it would be great if I could sync the keys between the ...