Questions tagged [custom-scheme]

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Can this scheme be circumvented?

I am currently developing software, in which players essentially make a "bet". While not exactly congruent to my situation, I will use the example of a randomly shuffled 52 card deck, in ...
Mama Raikou's user avatar
0 votes
2 answers

Does using subkeys provide better protection in this instance?

I was thinking of implementing the following scheme for encryption of many independent files: From the password, which is given by the user, generate a master key using for example HMAC-SHA. From ...
HerpDerpington's user avatar
0 votes
1 answer

Cryptographic File Storage scheme

First of all,I am new to security as a whole and taking my first formal course on it.So sorry if any major errors are present. I had a scheme for remote file storage as an attempt to use my course ...
Girish Srivatsa's user avatar
178 votes
12 answers

Why is it wrong to *implement* myself a known, published, widely believed to be secure crypto algorithm?

I know the general advice that we should never design¹ a cryptographic algorithm. It has been talked about very extensively on this site and on the websites of professionals of such caliber as Bruce ...
gaazkam's user avatar
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8 votes
4 answers

How much security expertise does a general application programmer need to develop software ethically? [closed]

I am curious about this. I saw this thread: Why shouldn't we roll our own? and this answer: which had on it this comment, which had the second ...
The_Sympathizer's user avatar
2 votes
1 answer

Slow Hashing Without a Salt?

I'm trying to design a security scheme that involves a shared secret but isn't a traditional account password situation. The server would store a set of "keys", each of which has a blob of data ...
Chris Graham's user avatar
0 votes
1 answer

What is the name of this token-authentication scheme?

I'm working on a specific security design. When reading it, it looks like some form of OATH but I'm not sure which kind. The scheme is as follows: The client authenticates through a web-portal (...
Bob van Luijt's user avatar
3 votes
1 answer

Is this a valid secure cookie scheme?

I have a scheme for a cookie with high-level confidentiality of information. The information to be hidden from the client is the expiration time of the cookie. I am wondering what insecurities i am ...
lluisrojass's user avatar
0 votes
1 answer

Does this authentication scheme exist?

For an IoT project I've defined a simple security schema. Does this already exsist and if so, how is it called? Definition: There is one root key. With every key, a child key can be generated....
Bob van Luijt's user avatar
0 votes
3 answers

Double-hashing authentication scheme

Rate my authentication scheme? (This feels simple enough to be a duplicate, but it's really hard to search for these types of questions. Sorry if it is a duplicate.) When a password is set, it's ...
Nathan Ringo's user avatar
2 votes
2 answers

Simple-to-implement ad-hoc password validation scheme

I'm writing a level for a game in which the player has an advantage if they know a password. I want it to be infeasible to find the password from looking at the level's source code. The problem is ...
cardboard_box's user avatar
-2 votes
4 answers

Roll your own encryption - with a twist

I am familiar with Schneier's Law: Any person can invent a security system so clever that he or she can't imagine a way of breaking it. I have read the many posts on this exchange littered with ...
RollYourOwn's user avatar
2 votes
0 answers

Distributed Shared Secret for RNG that only Distributor knows?

For one of my projects I want to create a way to sync up all participants' RNG with a seed where each participant does not know the seed of the RNG but also in a way that minimizes the number of times ...
sethmlarson's user avatar
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1 vote
1 answer

Is This DIY Password Authentication Scheme Acceptable?

This is mostly a thought experiment for client/server communication, and I want to know the flaws. When a user account is created (with U as the username and P as the password,) I generate a random ...
yzt's user avatar
  • 113
6 votes
2 answers

What are the weaknesses of my authentication scheme?

So, recently, after going through some infosec training (FutureLearn's Introduction to Cyber Security, which I heavily recommend as well-explained newbie material), I decided to take the plunge and ...
Hadrien G.'s user avatar
1 vote
1 answer

is this data encryption scheme viable?

My goal is to be able to encrypt the data so that no one would be able to make use of it if it was stolen. User data - the one that will be encrypted - can be any type of data Data encryption key - ...
Gene Diaz's user avatar
  • 113
3 votes
1 answer

What is this QR code authentication scheme called?

What is this pattern for mobile authentication called? It's more convenient than entering complex password on mobile phone, and I wanted to read about it more A user is authenticated within webapp ...
joozek's user avatar
  • 253
0 votes
1 answer

Where can I find a list of Indicators of Compromise (IOC) conditions? has several schemas defining Indicators of Compromise. The Schema is defined here: While under IndicatorItemContext/search says it is xs:...
A G's user avatar
  • 161
3 votes
1 answer

Are there any uses of having a non-deterministic salt value for hashes?

So I've been toying with the idea of having non-deterministic salt values for hashes. Let me explain what I mean: Basically, I applied some properties from Bitcoin including a "difficulty" (ie, ...
Earlz's user avatar
  • 604
5 votes
1 answer

Security and authentication problem

We have a sample scenario and we would like to receive some feedback and some solutions regarding possible security schemes. First of all, lets imagine a real world scenario: Imagine that a user ...
glarkou's user avatar
  • 169
10 votes
4 answers

Defense in depth vs low complexity - Balancing point?

I've asked a few questions relating to schemes for various security-related functions, and posited schemes to accomplish those goals. In the responses, I see a conflict between two fundamental ...
KeithS's user avatar
  • 6,768
286 votes
11 answers

Why shouldn't we roll our own?

Why shouldn't we create our own security schemes? I see a lot of questions around here about custom crypto and custom security mechanisms, especially around password hashing. With that in mind, I'm ...
Polynomial's user avatar
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