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1500 questions
105
votes
4 answers
Why is writing zeros (or random data) over a hard drive multiple times better than just doing it once?
Lots of different programs, such as Darik's Boot and Nuke, let you write over a hard drive multiple times under the guise of it being more secure than just doing it once. Why?
Tom Marthenal
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104
votes
5 answers
How does SSLstrip work?
I've been reading up on SSLstrip and I'm not 100% sure on my understanding of how it works.
A lot of documentation seems to indicate that it simply replaces occurrences of "https" with "http" in traffic that it has access to. So a URL passing…
Scott Helme
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104
votes
10 answers
Why is blog spam always written so badly?
Some spam messages fresh from my Wordpress filter:
Asking questions are in fact pleasant thing if you are not
understanding something totally, except this article gives good
understanding yet.
and
Thanks for any other informative blog. Where…
Lucas
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104
votes
3 answers
How are anti viruses so fast?
The common anti-virus (to my knowledge) uses a kind of brute force type method where they get the hash of the file and compare it to thousands of known virus' hash. Is it just they have servers with super fast SSD and they upload the hashes to that…
Harry
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104
votes
3 answers
Why do we trust US Certificate Authorities?
Why do people trust companies in countries with big surveillance programs like the US?
Many US Certificate Authorities secure the web for live SSL/TLS connections. Still, a NSL would be enough for the government to gain the right to intercept the…
Richard R. Matthews
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104
votes
2 answers
Can a rogue .wmv file "hijack" Windows Media Player?
I've downloaded a .wmv file using P2P. Attempting to play it with Media Player Classic (K-Lite Codec Pack) only gave me a green square in the playback window:
I noticed that the video came with a readme file, however; I found the following…
user4520
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103
votes
19 answers
How to explain to traditional people why they should upgrade their old Windows XP device?
This is an issue I'm recurringly facing: older people from my family (or people who my family members know) can be surprisingly reluctant to apply most basic security measures when they're using their PCs. The particular issues vary, but this time…
gaazkam
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103
votes
16 answers
Security BY obscurity is horrible. Is security AND obscurity good?
Normally I preach that rolling your own custom crypto algorithm is a bad idea. But will it really hurt if it's the outermost layer though? Or will it make security worse?
AES -> CipherText -> CustomEncryptionAlgorithm-> CipherText
I'm thinking…
user3280964
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103
votes
4 answers
What is ECDHE-RSA?
What is the difference between ECDHE-RSA and DHE-RSA?
I know that DHE-RSA is (in one sentence) Diffie Hellman signed using RSA keys. Where DH is used for forward secrecy and RSA guards against MITM, but where do the elliptic curves in ECDHE-RSA are…
Hubert Kario
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102
votes
10 answers
Unsubscribe safely
I have heard that is better to never click to any link in an email. Is it a bad idea to click to a unsubscribe link? What is the best way to unsubscribe to undesired mails?
Nrc
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102
votes
5 answers
Can I safely preview a short link?
There are a lot of different URL shorteners out there, like Bitly or TinyURL. Besides their main purpose of shortening a link, they also:
obfuscate the actual URL
collect statistics about the usage of the short link
From the obfuscation, at least…
stackprotector
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102
votes
4 answers
Why is this 435 × 652 pixel JPEG over 6 MB?
This was, before someone helpfully fixed it after seeing this question, a relatively unassuming and tiny photo of a ̶f̶i̶s̶h̶ nudibranch, with 283,620 pixels. It has some metadata: text Exif tags as well as 8.6kB of Color Profile information, and a…
David
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102
votes
3 answers
Why is Sojdlg123aljg a common password?
I was going through the list of top 100K passwords and found Sojdlg123aljg near the top of the list. Does anyone have any idea why this is such a common password?
azoundria
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102
votes
9 answers
Buying a "Used" Router
I am buying a "new" router from an open-box sale at a company that liquidates eCommerce returns. Plan to use it for a home network at cottage.
I'm a bit nervous that it could have been modified by whoever had it last.
What are the main risks in…
GWR
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102
votes
3 answers
Token-based authentication - Securing the token
I have developed a backend REST API for a mobile app and I am now looking to implement token-based authentication for it to avoid having to prompt the user to login on every run of the app.
What I had in mind was on the initial request the user…
James
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