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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5
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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 ...
-1
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3answers
417 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
vote
2answers
176 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 ...
1
vote
1answer
81 views

Mount ecryptfs directory via SSH

I have access to a server that I use for backups. I use rsync with the --delete flag to make an exact copy of my backup directory. I have no need for incremental backups. The backup directory on the ...
0
votes
1answer
124 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 ...
5
votes
2answers
199 views

ProtonMail security concerns

This TED talk brought me here. First of all, to those who created ProtonMail: Nice job!!. Regardless of what people say, it's definitely a big step forward from tradition options like Hotmail, Gmail ...
-4
votes
1answer
28 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 ...
1
vote
1answer
64 views

Difference between fully homomorphic and semi-homomorphic encryption

What is the difference between fully homomorphic and semi-homomorphic encryption?
4
votes
1answer
71 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 ...
1
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1answer
666 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 ...
6
votes
0answers
175 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 ...
29
votes
5answers
6k 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
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0answers
24 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 ...
47
votes
5answers
11k 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 ...
3
votes
0answers
272 views

What are the vulnerabilities of this homemade encryption algorithm? [migrated]

I decided to program a relatively trivial encryption algorithm in my downtime. This algorithm takes a seed from a user (supports floating point seeds), and then adds 1 to the seed for every iteration ...
1
vote
1answer
42 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 ...
1
vote
1answer
72 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 ...
0
votes
1answer
54 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 ...
2
votes
2answers
119 views

Save application autostart login token on computer

I need to login desktop application while autostart on server (like skype does). What is the best practice to save authentication token (password)? Should I use something like RSA encryption (which ...
2
votes
1answer
42 views

Authenticity of PDF document printed from Word

My MS Word Add-In generates PDF preview of DOCX file on client PC and uploads both files to server. I cannot generate PDF on server. Is there any way to make sure that the PDF is the printed version ...
26
votes
3answers
6k views

symmetric encryption session keys in SSL/TLS

This question concerns the session send and receive keys used in SSL/TLS protocol. my understanding is that this key uses symmetric encryption (DES, AES, BlowFish, etc.) I'm wondering, if ...
0
votes
2answers
59 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 ...
2
votes
3answers
137 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 ...
6
votes
1answer
6k 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
21 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 ...
0
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0answers
33 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
83 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 ...
15
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 ...
3
votes
1answer
145 views

Session Management for Private Key Passphrases in a Web Application

Use Case I would like to encrypt data in a database for a Web Application. The following requirements exist: Decryption should only be possible when a user provides a passphrase Encryption should ...
2
votes
1answer
226 views

Klein and PTW wep attack

I'm working on an implementation of Klein's wep attack. For that, I've set up a router with wep encryption and collected 50,000 unique IVs from it. I tried only calculating K[0], meaning - the first ...
23
votes
7answers
37k 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
93 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 ...
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0answers
35 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
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0answers
30 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
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2answers
147 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 ...
13
votes
3answers
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 ...
0
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2answers
96 views

Why do I have to use multiple Keys for each direction and purpose?

I'm currently writing an examen about 'Lessons Learned in the IT-Security'. I already found some thing, which shouldn't be done. But right now I'm in trouble finding the reasons why not to do so. ...
3
votes
1answer
139 views

Hashcat, finding out the Hash

I've been searching but I can't seem to find the much information on how to extract hash's from say PDF files or Lotus Notes files that I can then use in Hashcat? I know how to get them for Office ...
11
votes
1answer
1k 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
78 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
134 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 ...
2
votes
1answer
79 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 ...
0
votes
0answers
46 views

Is it safe to encrypt data by simply randomizing chunks based on a permutation? [migrated]

Say I want to encrypt the following text: "Today is March the 22nd, 2015". And say want to encrypt 8-byte blocks of data using the following permutation [6,3,0,1,5,7,2,4] to swap characters at those ...
2
votes
2answers
100 views

Converting ECC Private key to PKCS#1 format

Is there any way to convert an ECC private key to RSA PKCS#1 format? I have tried converting it to PKCS#8 first using OpenSSL: openssl pkcs8 -topk8 -nocrypt -in EC_key.pem -out pkcs8_key.pem This ...
0
votes
1answer
128 views

Storing encrypted data for offline use

A user downloads a file from a server. I want to store that file locally on the user's machine so they can view offline. For protection, it should be encrypted while not being viewed. My theory is ...
1
vote
3answers
118 views

Does Wifi encryption create a private tunnel between the adapter and the accesspoint?

When non HTTP/S data is sent over Wifi, can that data be seen by other machines that happen to also be connected to that same access point? Does the privacy of the HTTP data depend on the encryption ...
0
votes
1answer
442 views

Are temporary files an issue when opening and editing an encrypted 7z file?

I am new to security and encryption. I want to store important information like passwords and pin codes so I don't forget them. So far I have been using LastPass but I would prefer a solution I ...
2
votes
1answer
121 views

Is this a sensible way to encrypt user data?

I want to make a site for storing sensitive user data, that retains per-user data encryption in the event that the database is compromised. This is the model I was thinking of, to give the best ...
2
votes
1answer
73 views

Protecting a statistics endpoint

When we download an application - it asks us whether it's ok to submit statistics, error reports to the vendor. Since this data is sent from the application to server endpoint - I am wondering how ...
3
votes
1answer
446 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 ...