Linked Questions

5
votes
2answers
815 views

Why not slightly modify an existing hashfunction to create your own? [duplicate]

I read this interesting question on why improvising your own Hash function out of existing hash functions is bad. However this is specifically focusing on 'mixing' existing hashfunctions. What if for ...
0
votes
2answers
2k views

What is a good way to generate a one time pad, and is this a good way? [duplicate]

Is there a good/better/best way to generate a one time pad? I would like to only utilize about 40 characters (a-z, 0-9, .,!-). What I have come up with is perhaps not the BEST way, but seems to fill ...
1
vote
1answer
137 views

Where to submit an algorithm for analysis? [duplicate]

I'm developing a cryptographic toolkit and plan to employ custom algorithms for hashing, password stretching, etc. Is there a way I can get them analysed? Yes, I can post it on my website and on sites ...
1
vote
2answers
90 views

Reason for not implementing own algorithms/implementations [duplicate]

I get that people don't want to encourage other people to implement their own algorithms/implementations of algorithms due to safety issues. But on the other hand, questions about creating your own ...
68
votes
21answers
57k views

Lessons learned and misconceptions regarding encryption and cryptology

Cryptology is such a broad subject that even experienced coders will almost always make mistakes the first few times around. However encryption is such an important topic, often we can't afford to ...
92
votes
9answers
16k views

Does anybody not store salts?

We talked about password hashing and salting in class today. Our professor had a very different understanding of the use case of salts from mine and said that you might not store the salt at all and ...
80
votes
10answers
8k views

Why improvising your own Hash function out of existing hash functions is so bad

I'm afraid I'll have tomatoes thrown at me for asking this old question, but here goes. After reading that cooking up your own password hash out of existing hashing functions is dangerous over and ...
61
votes
7answers
13k views

Is it safe/wise to store a salt in the same field as the hashed password?

In using Argon2 for hashing passwords in my application, I've noticed it generates a string like this (e.g. for password "rabbit"): $argon2i$v=19$m=65536,t=3,p=1$YOtX2//7NoD/owm8RZ8llw==$...
27
votes
10answers
12k views

How to secure passwords over HTTP?

Say my password is abc. I want to send it to the server over HTTP. I could send it in plaintext and let the server hash it and compare it to the entries in its database, but then anyone that can see ...
39
votes
8answers
16k views

Is salting a hash really as secure as common knowledge implies?

(I did search on this topic, but I found no complete question/answer that addressed it, or even good portions of questions that might be relevant.) I'm implementing a salt function for user passwords ...
43
votes
11answers
7k views

Isn't all security “through obscurity”?

I know that one shouldn't rely on "obscurity" for their security. For example, choosing a non-standard port is not really security, but it also doesn't usually hurt to do so (and may help mitigate ...
73
votes
5answers
14k views

What makes Random Number Generators so fragile?

It seems to me that a hardware component which generates random numbers is extremely simple - just measure tiny vibrations in the hardware with a sensor, right? Maybe I'm wrong but it seems like if ...
25
votes
6answers
9k views

What would be the key size for a picture used as a key?

I'm working on a cryptosystem that uses colour pictures as keys for encryption. I'm trying to guess what is the key size of my cryptosystem in order to find the feasibility of a brute force attack. My ...
58
votes
4answers
5k views

What security risks are posed by software vendors deploying SSL Intercepting proxies on user desktops (e.g. Superfish)

There has been quite a bit of concern noted relating to the recent discovery that Lenovo are pre-installing a piece of Adware (Superfish) which has the capability of intercepting SSL traffic from ...
33
votes
3answers
7k views

Is using the username encrypted with the password as key a good password storage scheme?

On web applications I build I don't hash the passwords. Instead I symmetrically encrypt the username using the user's password and store the result in the password field. I use RijndaelManaged on ...
40
votes
5answers
55k 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 ...
33
votes
3answers
7k views

What does “in-house hash function” mean?

In security news, I faced a new term related to hash functions: it is reported that the "in-house hash function" used in IOTA platform is broken (i.e. Curl-P hash function). You can find the complete ...
32
votes
5answers
3k 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 ...
13
votes
4answers
4k views

Is this passwordless system secure?

A person has a form that asks for a name and password. The password is sent to the server where a hash is created from hashing the name and password. This hash is converted into a number using the ...
10
votes
3answers
9k views

How can i find what hashing algorithm was used?

One of my clients has asked me to modify the login page that their board members use to access their materials. The problem here is that the person previously responsible for this has left no ...
5
votes
2answers
2k views

Security of my homebrew hash algorithm [closed]

I am developing a 16 chars long hash algorithm. I have a second algorithm that generates random 1024 char strings. This algorithm loops and detects if there's a collision between the newly generated ...
20
votes
3answers
4k views

Using SHA-256 to preprocess password before bcrypt?

I would like to allow users of my web application to have long passwords, if they so wish. Today I became aware of bcrypt's password length limitation (72 characters, the rest truncated). Would it be ...
13
votes
2answers
3k views

Is this a secure data exchange scheme for a game?

I am writing a multiplayer game. I have a central server which processes everything. For data exchange I use HTTPS protocol. Because this is a game I cannot use computationally expensive systems like ...
15
votes
7answers
1k views

Has cryptography reached the development level where social engineering is the only reliable method of attack?

Note that for the purpose of this question, "social engineering" means extracting information from humans, be your methods compliant with Geneva Conventions or not. Simply put: Do cryptographic ...
3
votes
4answers
3k views

Sql database password encryption opinion needed

I am trying to understand if my database password encryption structure is good, or not much use. So when i register, the php will generate a 50 character random key, and that key will be put into a ...
15
votes
4answers
3k views

Why use random salts?

I read this blogpost on how to store passwords in a database, the secure way. Elbert tells us to do this: Generate a random salt and include something random and the username in it. Hash this. Hash &...
26
votes
4answers
4k views

Flaw in encryption through pseudorandom number stream (from PGP documentation)

I was reading PGP docs and came upon a part written by Phil Zimmermann (PGP's creator) that piqued my curiosity: When I was in college in the early 70s, I devised what I believed was a brilliant ...
17
votes
4answers
4k views

One Time Password Algorithm for Humans

Is there a one time password generation algorithm (based on predefined secret and a changing value/time/counter/etc) that is simple enough that it can be processed by an average human but safe enough ...
1
vote
3answers
3k views

Any hints for programming my own password manager? [closed]

I mostly want whatever help & suggestions you can give me about what I should avoid & what I should think about when making this. I'm a reasonable programmer & I want to make my own ...
1
vote
4answers
3k views

Encrypting text data by replacing characters?

I have been thinking on this method but did not really get into it because I thought it was stupid to do for some reason, maybe because I've never heard of it and it's pretty obvious. But today I got ...

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