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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2
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2answers
64 views

Why is GPG encrypted message size not proportional to number of recipients & file size?

I have noticed that when I am using GnuPG to encrypt a file for multiple recipients, the size of the encrypted message does not seem to be directly proportional to the number of recipients. For ...
2
votes
3answers
370 views

Easiest solution for automatic encryption of files on Dropbox?

I don't trust Dropbox to keep my files secure. In fact, the same goes for all the other file clouds. What I'd like is a easy and cross platform means of encrypting files that I add and read from ...
1
vote
1answer
90 views

“Inverted” asymmetric encryption

I am developing a system to prevent frauds in tickets. What do I need? An algorithm to generate a QR Code that will be shown to my clients in a ticket. An algorithm to validate (offline) the ...
1
vote
1answer
115 views

Android encryption when phone is on

So I have android lollipop installed, which should be encrypted automatically with some startup password. My question is, what happens if the phone get stolen while its on, and the screen is locked? ...
0
votes
1answer
86 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 ...
1
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0answers
37 views

FIPS Compliance with iOS app

Our company is working on getting FIPS validation for the iOS app and is in the initial phase. We have decided to use a private FIPS-certified libraries for using in the crypto modules. I have some ...
62
votes
11answers
14k views

Is there any technical security reason not to buy the cheapest SSL certificate you can find?

While shopping for a basic SSL cert for my blog, I found that many of the more well known Certificat Authorities have an entry-level certificate (with less stringent validation of the purchaser's ...
2
votes
2answers
275 views

PGP as method of sharing AES key?

Would PGP work as a method of sharing the AES key, as shown below, and what would be the flaws with this method of encryption? Server sends PGP public key Client generates (uses as AES key for ...
0
votes
1answer
261 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 ...
2
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0answers
39 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 ...
5
votes
1answer
249 views

Is email encryption, as claimed by ProtonMail, possible?

Is it possible to create a Web service that encrypts all messages, such that only the writer, and the person to whom the mail is sent, can read it? In other words, is the theory behind ProtonMail ...
7
votes
1answer
470 views

Is there a method to get plain-text from cipher-text in HMAC SHA-1, given that the key is known?

This is technically not even an attack. We have all the resources at hand, except for the original plain-text. We have the cipher-text (to be converted back to plain-text), as well as the key. The ...
3
votes
2answers
132 views

How can a connection be secure, if somebody observes it from the beginning? [duplicate]

If somebody observes a connention between client, and the server, then he can see the keys, by the following data encrypted is. As far as I know, if I connect to a server, then it sends me some keys, ...
0
votes
5answers
423 views

What if I develop my own hash algorithm to create strong passwords from easy ones?

I came up with this idea but I cant figure out if it's good or bad, maybe you can help. My goal is: I want to create extremely strong passwords for my main accounts (gmail, skype and so on). I want to ...
0
votes
0answers
46 views

Older Cell / Smart phones were susceptible to bluesnarfing / bluetooth attacks, Why specifically are smartphones secure from this attack now?

Older cell / smart phones were susceptible to bluesnarfing / Bluetooth attacks, Nokia phones in particular. But now in days, modern smart phone and cell phones that use Bluetooth technology for ...
2
votes
3answers
134 views

Are there any flaws in this two way cryptographic function?

I created a simple two way cryptographic function which allows you to encrypt a message and decrypt it with the same key. Here's how it works. Split the message into an array of 32-bit (or something ...
31
votes
5answers
2k views

Password Storage - Self Encryption vs Hashing?

Self Encryption: Encrypting a password using the password itself (as a symmetric key). Basically, by doing this, I'll get random data as an output. Now, in order to retrieve the password from this ...
8
votes
3answers
2k views

Does Android encryption really prevent law enforcement access?

Google recently announced that in Android L encryption would be turned on by default: For over three years Android has offered encryption, and keys are not stored off of the device, so they ...
1
vote
1answer
251 views

How strong is PDF security/encryption?

I want to securely convey a PDF document containing sensitive information from my system to another system. The latter is operated by a different person, whom I trust. However, this person does not ...
1
vote
1answer
131 views

Automate the process of giving a user access to his encrypted messages, when the user loses his password

I'm implementing a way for users to share messages with other users. All users and admin-users have a unique key pair. A message can be sent from one user to multiple users. Admin-users, who always ...
13
votes
4answers
5k views

Is “Why Should You Avoid AES In MySQL?” true?

From a 2012 Smashing Magazine article quite a bold statement is made to avoid AES in MySQL itself. Or as they put it "Why Should You Avoid AES In MySQL?". However, if you search for SQL encryption, ...
9
votes
4answers
6k views

ECDSA vs ECDH vs Ed25519 vs Curve25519

Among the ECC algorithms available in openSSH (ECDH, ECDSA, Ed25519, Curve25519), which offers the best level of security, and (ideally) why?
-2
votes
0answers
15 views

How to compare security parameters of different schemes (Sign-Encrypt, Encrypt-Sign, etc)? [migrated]

How can one compare the security parameters (confidentiality, integrity, non repudiation, etc.) for different schemes (Sign-Encrypt, Encrypt-Sign, Sign-Encrypt-Sign, Encrypt-Sign-Encrypt)? Are there ...
0
votes
1answer
116 views

Thunderbird password decryption from the signons.sqlite and keys3.db without using any third party tools

I understand from the Mozilla documentations that the passwords are stored in the following two files which are located at ~/.thunderbird/*.default location: ( I use Ubuntu 13.10) signons.sqlite ...
2
votes
2answers
58 views

If a phone is encrypted at a platform storage level do I need to encrypt my data stored on it?

I am writing a mobile app which would be expected to store sensitive data. It needs to be stored for offline use. I am wondering now that Android and iOS provide encryption at rest do I need to ...
7
votes
5answers
6k views

What is the most secure way for two people to communicate?

There are various services on the internet that offer secure communications. Typically in the past if I want to share some sensitive information with someone, I will do so over a Cryptocat chat ...
2
votes
2answers
82 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 ...
0
votes
1answer
145 views

How to secure my REST API once user authenticates with Google on mobile client?

In my application, I build REST APIs so that user can interact with my application server. Since I do not want to maintain User/Passwords, my iOS app authenticates client using Google. This all ...
0
votes
1answer
40 views

How are Cloud based HSMs used for Encryption by an application that is on premise (behind the enterprise firewall)?

Amazon CloudHSM (It is Safenet in the backend), Safenet Luna HSM SaaS version and other cloud HSM providers provide Key Management and encryption services on device in the cloud. From my research, I ...
1
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1answer
93 views

Algorithm to Transaction Data Signing

Transaction Data Signing I need an idea to develop a very secure algorithm to authenticate online operations using PHP in the server and an Android app in the user's device. What is the idea? The ...
1
vote
1answer
75 views

secure private key storage

in recent light of badusb storing private keys on a usb flash drive is not the best way what about writing private keys to a cd? what i am worried about is whenever i plug my private key storage ...
0
votes
2answers
108 views

Protection of Private Keys

I've used mail encryption products like Mailvelope in the past, where you have to create a key pair to encrypt/decrypt data. I understand you have to hand out the public key to others that want to ...
2
votes
0answers
83 views

How does firefox sync password recovery work?

According to Mozilla Sync-new-security-model, Firefox servers are not able to decrypt your sync data without your password. So I figured that, the browser generates a key from your password, encrypts ...
0
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2answers
107 views

Trust level of whole disk encryption software

For example, if we take this software into account: Symantec Endpoint Encryption Sophos Safeguard Encryption How can we trust suppliers of whole disk encryption software in the lights of the ...
1
vote
1answer
61 views

Secure voice app [closed]

When I look in the Google play store (android apps market), I see that there are a lot of apps to make secure phone calls. However, all the apps I have seen so far all seem to use data packets over ...
1
vote
0answers
19 views

Encrypt Lightning event invite mails with pgp [migrated]

I use Thunderbirds/Icedoves Lightning add-on to manage my calendar, tasks and notes. When creating an event I can add attendees and send invitations to them, but they won't use their public pgp keys ...
0
votes
1answer
66 views

Ensuring security of web based games and contests

I have previously analysed an online contest and found that it was trivial to reverse engineer the handshake process since it was all done in javascript. As a result, it was possible to code an ...
0
votes
4answers
190 views

How safe is it to use older/unknown Encryption methods for plaintext?

When mailing or chatting with people, it had crossed my mind, what if, for simple communication, someone would use an older encryption method (i.e., ENIGMA), to encrypt their message? Would because ...
0
votes
2answers
109 views

typical request, what type of encryption is this? [closed]

so our company's CTO quit, and i replaced him and we need to change the system's passwords, however some passwords are encrypted in our database and i need to know what encryption to use in order to ...
0
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0answers
80 views

Cryptolocker virus removal [migrated]

I am facing cryptolocker virus problem, I have tried decryptcryptolocker website but it did not work. In the below link you will find an example encrypted file in my pc. ...
2
votes
3answers
137 views

Can a form submission be encrypted even though address bar shows HTTP?

I was going to apply for a Student ID card through ISIC, but noticed that the form where they ask for payment (such as credit card number) details is not available through HTTPS. The URL to their ...
0
votes
1answer
118 views

Securing user postal address in a database?

I've been assigned a web project that deals with shipping goods between two parties. I am unsure what a secure database scheme (if any) would be for storing the recipient's postal address and whether ...
0
votes
2answers
78 views

Lock And Unlock Files Using USB Key

I am looking for a way to make a set of files only able to be read when a USB key is plugged into the system. For example, if I have FILE A on my C drive and I try to open it, it will say something ...
1
vote
1answer
101 views

All users can write only one can read system

The system I want to implement has the following requirement: All users can insert some sensitive data, but only one, master user, can see it. There is any known, already implemented solution to this ...
3
votes
1answer
70 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 ...
1
vote
0answers
89 views

Understanding Java Security Providers

I'm hoping to use the below issue we came across recently to better understand Java's security providers, ciphers and encryption in general. We got the following error during an SSL Handshake (using ...
2
votes
1answer
155 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 ...
11
votes
10answers
16k 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 ...
2
votes
1answer
42 views

Do I need to save the IV generated to the database?

I see plenty of answers for what and how to use IV. But is it important to keep the IV saved for decryption? I would think so, but I haven't seen anyone saying anything about this. If you want a ...
21
votes
4answers
3k views

How would you store a 4 digit pin code securely in the database?

I'm familiar with password hashing, using salts, bcrypt etc. But it doesn't seem like this would work to store a 4 digit pin code since the attacker could try all 10,000 combinations quite quickly. ...