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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11
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7answers
3k views

What's the safest way to transmit a message to another client through a server hidden from high level malicious users? [closed]

Suppose you're constantly being menaced by high profile hackers and agencies that try to intercept messages sent between you and a friend. The question is: what's the safest way to send messages to ...
1
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5answers
673 views

Authenticate user without knowing their password

I'm working on a project where each each user will have a public/private RSA key-pair. Users will be able to send encrypted messages to each other using the each target user's public key so that only ...
35
votes
5answers
50k views

Advantages and disadvantages of Stream versus Block Ciphers

Encryption algorithms such as Blowfish,AES,RC4,DES and Seal are implemented in one of two categories of ciphers. What are the advantages/disadvantages to the type of ciphers?
5
votes
4answers
2k views

How to roll my own security mechanism - avoid SSL

i'm looking at implementing my own security mechanism rather than using ssl due to ssl being 'hopelessly broken' http://www.theregister.co.uk/2011/04/11/state_of_ssl_analysis/ and also because it is ...
0
votes
3answers
786 views

Which PHP encryption method is most incidentally-secure?

just started researching on the latest PHP encryption methods, I've found out my favorite algorithms are compromised. MD5 is no good, SHA-1 has "found flaws", SHA-512 isn't "meant for passwords", ...
1
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2answers
269 views

Is SpiderOak truly “zero-knowledge”?

I've recently changed SpiderOak password on computer A. Because I have SpiderOak installed on computer B as well, I thought I will have to update the password on it so the application can connect to ...
-4
votes
1answer
55 views

What is the most secure way to protect a custom CMS from infiltration? [closed]

I have a custom CMS with a randomly generated ASCII 100-character string from this site for both my username/password. I also have this following sha512 encryption system, which was created by ...
5
votes
1answer
137 views

Can I check who can decrypt my GPG message after I encrypt it?

When I send, say, a great recipe for funnel cake to Alice and Bob using GPG, I can be pretty sure they will both be able to decrypt it. However, can I be certain, or prove after the fact, that they ...
7
votes
0answers
294 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 ...
32
votes
5answers
11k views

How do I verify that WhatsApp is using end-to-end encryption?

Slightly old news: Whatsapp Just Switched on End-to-End Encryption for Hundreds of Millions of Users Is there any test that I can perform to verify that WhatsApp is indeed using end-to-end encryption ...
1
vote
0answers
46 views

Is a direct SIP video call (encrypted) between two computers more secure than going through a registrar service?

I learned recently about ZRTP-encrypted video calls using an SIP client, such as Jitsi or Linphone or Blink. I was able to make a direct encrypted video call between two clients on the same local ...
52
votes
5answers
13k views

Why should one not use the same asymmetric key for encryption as they do for signing?

In an answer to a question about RSA and PGP, PulpSpy noted this: It is possible to generate an RSA key pair using GPG (for both encryption and signing -- you should not use the same key for ...
1
vote
1answer
90 views

Secure point to point remote access to NAS drive

This question is very similar but also distinctly different (How do I ensure data encryption on Samba transmission on *NIX systems?) I'm looking to set up remote access to a NAS unit locally sharing ...
0
votes
1answer
73 views

Decrypting encrypted traffic with hacking an app [duplicate]

I am thinking how does telegram ensure that messages are secret. I understand they use the public key to encrypt and private key to decrypt. Why is it not possible for an attacker to download the ...
0
votes
2answers
74 views

Is End to End security possible without physical contact?

I noticed that a lot of messaging start to provide "End2End" security, but I wonder how this can be possible without a key exchange between the the two clients. To my understanding to provide real ...
3
votes
3answers
161 views

Acceptably secure solution for users to log in with a short unique code only (no username)

I am creating a website whereby users are given an account by invitation only, and are sent a unique code by post. Users can then log in (at least the first time) by entering the code only. The goal ...
7
votes
1answer
7k views

Are there any known vulnerabilities in PPTP VPNs when configured properly?

PPTP is the only VPN protocol supported by some devices (for example, the Asus RT-AC66U WiFi router). If PPTP is configured to only use the most secure options, does its use present any security ...
0
votes
0answers
24 views

Securing decentralised cloud scaling

Approach Require a certain percentage (quorum) of nodes to agree in order for my decentralised multicloud to grow. Benefits Reduced likelihood of growing too quickly (e.g.: 2 new nodes created ...
1
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0answers
60 views

Hiding symmetric key inside encrypted data

My server generates an AES encrypted file which when downloaded acts as an input for an application. So, should I hardcode the symmetric key inside the application or should I randomly generate the ...
3
votes
1answer
154 views

Asymmetric / end to end encryption for web messaging app

Background I'm trying to design a secure and sustainable web app for messaging. The purpose is to learn how to create secure web application. The application is suppose to be written in Javascript ...
16
votes
9answers
3k views

Hide the fact of e-mail communication

Bob has a mistress. Her name is Alice. Bob`s wife Eve knows Bob is unfaithful, but she does not know who the mistress is. Alice does not know Bob is married. Bob needs to communicate with Alice over ...
23
votes
7answers
39k views

How secure is a Windows password protected zip file?

I need to send some sensitive information to a client. I thought I would email a password protected zip file I created using Windows XP and then call them with the password. Presuming I pick a good ...
3
votes
0answers
109 views

Generate secure one-time codes containing information

I need to create a system that allows a user to enter codes to charge an allowance. Embedded in this code should be the amount to charge the allowance. The user would pay for a code which would then ...
2
votes
0answers
76 views

OpenID Connect: Why use authorization code flow?

I have a question about implementing OpenID Connect I was hoping I could get some help on. I understand the different flows and get that the authorization code flow is good because it allow client ...
4
votes
0answers
56 views

Is there any reason to use AesManaged over DPAPI in this scenario?

I have a situation where my web application is going to be deployed on multiple web servers, and I'll be wanting to store some securely encrypted data on the DB servers (each web server has a DB ...
0
votes
2answers
163 views

Is this the most secure encryption/hashing system? [closed]

I've been doing some research regarding password security and after reading several topics and the Kerckhoff's principle. I came up with what I believe is a really secure system regarding online ...
14
votes
3answers
5k 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 ...
11
votes
1answer
2k views

Why can't I use the same key for encryption and MAC?

I wrote a simple file encryption program as an example of how to do encryption correctly, but after reading a questions about encryption + MAC, I think I made a mistake by using the same key for both. ...
0
votes
1answer
85 views

Safely encrypting data received through HTTPS

I am receiving sensitive data over an HTTPS connection and need to store this on disk, encrypted so no one can tamper with it, but for reading later on. Each user in the system has a password. The ...
2
votes
2answers
136 views

Which hard disk encryptions schemes are tied to the original hardware?

When using a laptop, an encrypted HD/SSD can be an important security measure. However, laptops are prone to accidents (fluid spills, dropping on the floor, etc) that may mandate some or all of the ...
3
votes
1answer
463 views

Why does GnuPG shrink my file after elgamal encryption?

I would like to run GnuPG elgamal encryption for at least a few minutes. The only way I can think of is to create a large file to be encrypted. So I created my file like this: dd if=/dev/zero ...
1
vote
1answer
88 views

What is the safest way to encrypt a password that can be decrypted at a later time?

In a web app I'm building, I need to use Apple's AutoIngestion tool for iTunes Connect. In this tool it seems the only way to use it is to send a password in plain text. What would be the best ...
29
votes
4answers
22k views

How does PGP differ from S/MIME?

Is S/MIME an abstracted system for general MIME type encryption, whereas PGP is more for email? Why would I want to choose one over the other, or can I use both at the same time?
3
votes
1answer
182 views

Has the POODLE SSL vulnerability ever actually been used?

Is there any evidence that the the POODLE SSL or TLS has actually been proven to be a risk for file transfer like SecureFTP etc...? ...or is it just a theoretical exposure?
0
votes
1answer
61 views

Security at application layer

Originally asked on http://crypto.stackexchange.com/questions/24430/security-at-application-layer but was suggested to ask here instead. I saw lots of questions asking about encryption over http, ...
2
votes
2answers
1k views

What are the security implications of the POLi Internet Payments technique?

POLi Payments is an Australian based online payment provider which has begun trading in New Zealand. They are supported as a payment option on some large eCommerce websites in New Zealand, including ...
15
votes
4answers
15k views

Is RedPhone a secure and secret way to communicate?

RedPhone provides end-to-end encryption for your calls, securing your conversations so that nobody can listen in. But really, how is the probability that a voice conversation is wiretapped still? ...
2
votes
2answers
87 views

Does changing the default number of iterations in KeePass (or other encryption applications) increase security?

Inspired by this question about the difficulty of cracking a KeePass database, I'm wondering if changing the default number of iterations in an encryption application (e.g., KeePass) increases ...
7
votes
3answers
42k 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 ...
1
vote
1answer
78 views

What's the value of data partition encryption for database files on a postgres database server?

We're in the process of rolling out a postgres based web app, and I'm trying to understand the value of encrypting the entire database. In postgres's case, the only way to do this is store the ...
4
votes
1answer
75 views

Is it possible to prove the content of an encrypted message without disclosing the private key?

Suppose that I sent Bob a message saying, "The meeting is cancelled", and encrypted it with his public key. Could he share the plaintext with other people, without disclosing his private key (and ...
0
votes
1answer
176 views

Why my files that Encrypted with EFS in Windows 8.1 shown in Linux ubuntu?

i Encrypted my files with EFS in windows 8.1 so i logged in ubuntu and without any warning , its shown my files actually not Exactly the file but shown the path of file and the name and i can ...
52
votes
4answers
6k views

What kinds of encryption are _not_ breakable via Quantum Computers?

There's the recent article NSA seeks to build quantum computer that could crack most types of encryption. Now I'm not surprised by the NSA trying anything1, but what slightly baffles me is the word ...
5
votes
1answer
301 views

What are the security differences between SMIME email and PGP email? [closed]

Outside of key distribution, and specific to the technical details relating to encrypted email data (message body), what's the difference between SMIME and PGP? Example comparisons Security ...
13
votes
6answers
5k 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 / ...
1
vote
1answer
55 views

Is there any College, State or Government ID that transmits a offline verifiably encryptable data blob?

I'm looking for any way to digitally verify a user, ideally with a photo and link PII to that user. My use case is that a user will extract and send an encrypted data blob (say from a passport) to my ...
16
votes
4answers
3k views

Is it dangerous to publicly share ciphertext?

Alice wants to share a message with Bob, but Alice and Bob can never be in the same place at the same time. We can assume they both know each others public keys (or agreed on a shared key, if that ...
0
votes
1answer
76 views

WPS and WPA2 connection methods

Do clients use WPS every time when they connect to a WPS-enabled AP? Or maybe they do it just the first time and then they switch to a normal WPA/WPA2 key exchange? If the latter, it's possible for ...
2
votes
2answers
301 views

What is a current best practice example of basic encryption and decryption in PHP?

I have a good working knowledge of basic security best practices (password hashing, preventing sql injection, CSRF, etc.) but am completely at a loss for finding a solution to common-case encryption ...
19
votes
1answer
544 views

How to encrypt in PHP, properly?

How do I encrypt data in PHP, properly, using symmetric-key encryption? I have a message M and a secret S. I'm looking for a solution that uses cryptography properly without making any of the usual ...