7,470 reputation
12137
bio website github.com/CodesInChaos
location Frankfurt, Germany
age
visits member for 4 years
seen yesterday

NSA running around with their hair on fire because they realise if everyone starts using OTPs and not their weak AES algorithm then their PRISM programme is worthless. --- zuallauz - Would this simple encrypted chat program be feasible using One Time Pads?


2d
awarded  Yearling
Jul
28
awarded  Constituent
Jul
26
comment Why is my internal IP address (private) visible from the Internet?
@Boann Didn't he co-author about every second TLS related RFC? So the NSA related RFCs might just be by-products of his generally high TLS related activity.
Jul
25
comment Why is my internal IP address (private) visible from the Internet?
Because Mozilla&co don't give a damn about your privacy. They prefer Firefox silently acting as spyware over bothering the user with a prompt.
Jul
24
comment Encryption of settings/credentials in mobile apps - what threats does this protect against?
"What threats does encrypting like this protect against?" - "None." It's that simple.
Jul
17
comment Is it safe to send SSL certificates via email?
@halfer A certificate is signed by the CA and contains your public key and some meta data, like your domain name.
Jul
15
comment Is it helpful to have a captcha on a login screen?
@bishop What do you base the delay on? The username leads to a trivial DoS attack and IPs don't work so well either when faced with a botnet which consists of many zombies.
Jul
15
comment Why do we use passwords on sites?
@immibis Even if TLS is used for emails it's very rarely protected against MitM/downgrade attacks.
Jul
14
comment where to store the salt for “crypto_pwhash” in a web application with no local storage
The password itself is equivalent to not using a salt at all. The username combined with your site name is decent. You can combine it with a salt stored on the server which the client can query before logging in.
Jul
14
awarded  Caucus
Jul
8
comment Is Rfc2898DeriveBytes using HMAC SHA1 still considered “secure enough” for hashing passwords?
"when used in HMAC" is a bit misleading in this context. With PBKDF2 the use of HMAC is useless at best (and costs a factor 2 with many implementations, including Rfc2898DeriveBytes). The reason why SHA-1 is fine in PBKDF2 is that collisions don't matter against password hashes.
Jul
8
comment Is Rfc2898DeriveBytes using HMAC SHA1 still considered “secure enough” for hashing passwords?
The biggest weakness of Rfc2898DeriveBytes is that its implementation is slow, so you can only use a relatively low iteration count.
Jul
7
comment How to implement encrytion/decryption system using IV between mobile app and web service
Why don't you simply use TLS?
Jul
7
comment How does malicious software encrypt victims' files?
@loneboat Hashing algorithms used to check file integrity aim to be as fast as possible without sacrificing security. It's Only password hashes are deliberately slow, but there is no reason to mention those here. Hashes and symmetric encryption have similar performance and both are usually IO bound. Since hashing only needs to read the file, but encryption needs to read and write data, encryption should be about twice as expensive in this context.
Jul
5
comment Block chaining modes to avoid
"average size of a cycle should be around $2^{n/2}$" are you sure about that? I thought it's $2^{n-1}$ because a block cipher is a permutation not a random function.
Jul
1
comment Verifying cryptographically signed files when the key has been revoked
One approach is using a timestamping server when signing and checking if the key was valid back when the signing happened when verifying the signature.
Jul
1
comment Asian websites don't use HTTPS
Korea use to have an atrocious ActiveX based encryption system (not sure if they finally got rid of it).
Jun
30
comment Why do some programming language API's not support private key passwords?
Looking at the source, you should be able to replace it with slightly more complex code that supports multiple certificates and in memory private keys.
Jun
30
comment Why do some programming language API's not support private key passwords?
1) The benefit of encrypted private keys is relatively small since now you need to pass the password to the server, which on a server typically means storing it. 2) No idea. When I'd design such an API I'd certainly accept some kind of in-memory private key. Perhaps this is just the high level API designed to get you started quickly and there is a lower level API that gives you more flexibility.
Jun
23
awarded  Guru