Specific to the security of passwords: hashing, entropy, cracking, resets, lockouts, etc.

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7
votes
2answers
2k views

How does the attacker to ransomware get the password?

I have been thinking about ransomware and as I see it the password seems like it should be a problem for the attacker. I can see it going down one of two ways. Either the password is included in the ...
6
votes
6answers
2k views

Ransom attacks - can I protect myself by encrypting all my files?

If I encrypt all my files can I get "attacked" by ransom attacks? Because my files are already encrypted, they cannot access them, so I should be safe or am I wrong? Also, if someone could tell me ...
1
vote
0answers
71 views

Fido: trusting user-agent

As I went through Fido specifications: the server (providing web app/services) need to trust user agent for local fido authentication and if needed can enforce certain policies" I am not sure ...
7
votes
2answers
3k views

Practices for storing username/password in Web applications

I have read the following question: Storing password in Java application but I don't find the answers useful for my case. So here is my question somehow related to that. I have a Java Web application ...
10
votes
3answers
896 views

Calculating how secure my password is

I generally use GnuPG for encrypting my files and as far as I know its strength ultimately depends on the passphrase I use. So, I would like to know: how can I mathematically calculate how secure my ...
4
votes
1answer
739 views

How is the iCloud keychain protected from unauthorized access?

With OS X Mavericks and iOS 7.0.3, Apple has introduced a new feature called iCloud keychain. During setup, you can choose an iCloud Security Code. This code is used when you want to grant access to ...
0
votes
2answers
70 views

Several hashing routines support client side work. Doesn't the hash just become a password equivalent?

Isnt Secure Remote Password Protocol (SRP) pretty much client side hashing? Argon2 the winner of the PHC also allows for client side hashing. How do these systems avoid the plaintext equivalence ...
-1
votes
0answers
30 views

Is it possible to phish a wifi password using a fake AP? [duplicate]

If I were to create a fake AP with password and give it an SSID like the real AP using a program like hostapd,then when clients connect to this fake AP , they will type the real password and send it ...
3
votes
1answer
120 views

How to implement application-specific passwords using strong hashes?

I am implementing a service where application-specific passwords seem a good choice to improve security. A question on why and when they might make sense has already been discussed here Google ...
5
votes
1answer
116 views

How long does 2-factor authentication codes have to be?

I've noticed that from a (personal) UX point of view, 4 numbers which my online banking uses seems to be a sweet spot in terms of holding it in my head from looking at my phone to typing it it. But ...
3
votes
2answers
433 views

Secure database password stored in an env variable

I need to somewhere store my DB password on my production environment to access the DB. At the moment the prod system is deployed in the cloud, so is the DB. The password, the username and some other ...
-1
votes
0answers
21 views

Site to report password security policy issues [duplicate]

I just got an email from a site after I created an account and they emailed me back my password. I was shocked as its a pretty big eCommerce vendor and they broke such a common sense security rule. ...
5
votes
1answer
61 views

Unique Touchscreen Authentication Schemes

I am working on a new software application that will have access to millions of patient medical records. I want this to be secure. The initial thought process was to simply use a standard username ...
1
vote
1answer
73 views

Am I encrypting and storing an array of user-details correctly?

I came up with a user-details-storing procedure that was, in the beginning, based on actual security-literature – but then I just kept writing without really doing all the cross-checking I should have ...
5
votes
4answers
379 views

Best way to store/retrieve sensitive key files?

We have our web servers running in AWS EC2. We have about 30 API Keys/passwords/etc (sensitive data) which is set in the environment for our app to use. Whenever we deploy, we start a new server ...
7
votes
2answers
486 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 ...
7
votes
1answer
304 views

Any problems with scrypt yet?

In the question Do any security experts recommend bcrypt for password storage? Thomas Pornin recommends the hashing function scrypt but saying it is "too new to be recommended on a general basis". ...
691
votes
22answers
139k views

XKCD #936: Short complex password, or long dictionary passphrase?

How accurate is this XKCD comic from August 10, 2011? I've always been an advocate of long rather than complex passwords, but most security people (at least the ones that I've talked to) are ...
55
votes
12answers
11k views

What to do about websites that store plain text passwords

I recently received an email from a popular graduate job web site (prospects.ac.uk) that I haven't used in a while suggesting I use a new feature. It contained both my username and password in plain ...
369
votes
14answers
60k views

What technical reasons are there to have low maximum password lengths?

I have always wondered why so many websites have very firm restrictions on password length (exactly 8 characters, up to 8 characters, etc). These tend to be banks or other sites where I actually care ...
2
votes
3answers
140 views

How does a hash which contains algorithm to choose can be secure?

I was thinking about creating my own hash+salt function, something like sha1(password + md5(login)), then I read here (part 4) that creating it's own hash+salt function is a bad idea, because if the ...
0
votes
3answers
64 views

Password help with coding! [duplicate]

So, I'm terrible with any sort of coding, and I need help with generating a series of possible passwords. I've forgotten the combination of a password I put in for an email - I know the password, just ...
24
votes
10answers
5k views

Best password strength checker

In XKCD #936: Short complex password, or long dictionary passphrase? Jeff claimed that password cracking with "dictionary words separated by spaces", or "a complete sentence with punctuation", or ...
362
votes
21answers
69k views

How does changing your password every 90 days increase security?

Where I work I'm forced to change my password every 90 days. This security measure has been in place in many organizations for as long as I can remember. Is there a specific security vulnerability ...
2
votes
1answer
57 views

How to securely derive a second password specific to an user

I'm giving each of my users an unique Blocktrail wallet that is protected by two API keys (which the server knows) and one passphrase (unique to each wallet). I want the wallet's passphrase to be ...
4
votes
7answers
4k views

Pronounceable Password Generator

I am currently looking for a password generator which produces pronounceable passwords. I have used this random password generator a few years ago to generate a 42 characters long password and found ...
1
vote
3answers
75 views

How do I allow only app to view/download files from server?

I have an Android app that uploads and downloads pictures from my dedicated server. However, before I go live, I want to know if there is some way I can secure the server to allow only my app to ...
77
votes
12answers
15k views

Password rules: Should I disallow “leetspeak” dictionary passwords like XKCD's Tr0ub4dor&3

TLDR: We already require two-factor authentication for some users. I'm hashing, salting, and doing things to encourage long passphrases. I'm not interested in the merits of password complexity rules ...
6
votes
0answers
97 views

Which format of secret would be the most efficient for human memory? [closed]

I am talking about something-you-know identification factor. Examples of those formats are passwords, passphrases, pin-s, picture passwords ( ...
1
vote
2answers
133 views

Password Manager use and safety [duplicate]

I just recently read an article advocating the use of password managers, and while I understand why someone might think using these programs might be a good idea, it's my understanding that these ...
11
votes
5answers
2k views

Is this idea for a password manager secure? If so, why doesn't anybody use it? [closed]

I've been thinking of a problem with usual password managers: although they do provide better security than manually using passwords, there's a central database that can get lost, get compromised, ...
7
votes
2answers
1k views

Is it bad practice to ask only for individual characters of a password? [duplicate]

Some financial websites that I use use passwords in a peculiar way. Instead of asking me the whole password string, they only ask me to enter e.g. "3rd, 5th and 8th character of your password", i.e. a ...
0
votes
2answers
75 views

Random characters and letters form obsfuscation

I know that this question has been asked many times, but would JavaScript encryption work if I just added 100 random numbers and letters to the password? That would be hard to reverse engineer, ...
5
votes
1answer
229 views

Security of Yahoo's new authentication: On-demand password

Yahoo is trying to remove passwords from authentication and use on-demand password authentication system instead. I wonder how this new system will be secure? Even if somebody steal your mobile can ...
1
vote
4answers
70 views

Is it safe to use my personal password as my password in work related accounts?

For example I have this complex personal password cary1bondoc21cary2bondoc as my password and because I am forgetful I also want to used that in work related accounts like company email, etc. Is there ...
4
votes
5answers
217 views

How many combinations does a specific password policy allow?

Recently I was arguing about password policies. Assume you have a policy which requires 10 characters and additionally at least one letter, one number and one special character. My companion was ...
6
votes
1answer
194 views

What are the pros and cons of using sha256 to hash a password before passing it to bcrypt?

My apologies if this has already been asked. I recently became aware of the fact that bcrypt truncates passwords to 72 characters. Practically speaking my intuition is that this does not pose any ...
35
votes
11answers
6k views

Is it good practice to send passwords in separate emails, and why?

I have heard from different people and in different places that if I send an encrypted file to someone else, I should send them the password in a separate email; but why? If someone is sniffing, they ...
18
votes
4answers
4k views

Should I implement incorrect password delay in a website or a webservice?

With arguments expressed in this answer, there is a few seconds delay between user enters an incorrect password and when he/she actually learns, that password was incorrect. This security solution is ...
10
votes
4answers
3k views

SSH key auth, but still need password for sudo?

SSH with public-private key authentication comes enabled by default with most Linux distributions. This is great because when I create accounts for remote users I don't have to email them sensitive ...
5
votes
3answers
383 views

How to find passwords in memory (password managers)

I’m trying to figure out if password managers such as last pass store passwords in plain text (or hash values that can then be decrypted with the master password) in memory after a user logs into the ...
5
votes
2answers
90 views

Possible way to extract sudo password from running system via the clipboard

I use to copy and paste my sudo password from a KeePass file so I guess the plain text user password will be saved in RAM at some point when I use it, for example, to accept an update. Is that right? ...
1
vote
3answers
98 views

Sensitive issue regarding windows 8 password [closed]

Although I know this sort of request probably isn't exactly what stackoverflow is for, I am desperately seeking help. One of my best friends recently passed away and his parents asked me if I knew a ...
2
votes
3answers
113 views

Use the same password on different (very secure) sites?

I understand that one should not use the same password everywhere, as stated here for instance. Using the same password on several non-valuable sites may be considered acceptable: we simply do not ...
5
votes
5answers
2k views

Salted password + hash - is it really useful? [duplicate]

I am new to the topic and wanted to know the concept of having salted hashes before going down to the technical details. From what I have understand password - plaintext hash password - plaintext ...
7
votes
8answers
646 views

Password reset with lost email functionality

I have searched and viewed most of the other questions and answers about implementing forgot password functionality on a website. However, we have a unique situation. When a user registers an account ...
4
votes
2answers
237 views

Does adding a non-entropic part to a password makes it less secure?

Suppose I'm encrypting a file via AES using a password of my choice, or creating a TrueCrypt volume using a password and no keyfiles. Which of the following two passwords would be more secure: ...
1
vote
1answer
65 views

Prevent brute force attacks on web publishing logins

Presumably, if someone tries to brute force into your website's control panel at your web host's site - they will be throttled/locked-out etc. But what about the web publishing logins (Web-Deploy, ...
4
votes
2answers
468 views

Passwordless login over email - security considerations

I'm proposing the use of a login system that sends a one-time login token (with high entropy) via email to the user. After using the token, the user receives another token via email and the previous ...
2
votes
1answer
100 views

Is it secure to set default value for password field?

I'm looking at an application where admins can "invite" users by email and invited users. Invited users then are sent a unique URL and are inserted into a MySQL database with status pending and an ...