1,439 reputation
615
bio website paul-ebermann.tumblr.com
location Berlin, Germany
age
visits member for 2 years, 3 months
seen May 17 at 22:34
stats profile views 105

Don't fear to edit my posts: even if I have more reputation than you, I do make mistakes.

I'm now also a Moderator Pro Tempore (= until the first elections) at Cryptography Stack Exchange: feel free to come around and ask some cryptography questions.


My personal name is spoken as /ˈpawlo/ (IPA), in English this would be written similar to Powlo, I think (i.e. the vowels are ow and o), with an accent on the before-last syllable (which is the first in this case). It's the Esperanto form of my given name.

The photo shows my shadow, taken at night. My camera sometimes seems to forget all the other frequencies and only stores the green ones.

My current main private programming project is the game of fencing, an online abstract turn based strategy game. Implemented as a Java applet, using git as a version control system.


Some more links:


Apr
6
comment Is my developer's home-brew password security right or wrong, and why?
@qarma HMAC is using the secret (i.e. the password) twice, this algorithm is using it only once.
Apr
3
comment How quickly can these password schemes really be beaten?
@StephenTouset Good point, I added some text relating this to the answer. Seems I missed this part of the question.
Apr
3
revised How quickly can these password schemes really be beaten?
expanded
Apr
3
revised How quickly can these password schemes really be beaten?
add some information from the comments.
Apr
2
comment Password and Generated number - How does it work?
I didn't downvote, but I suppose someone didn't like the "RTFM" attitude (which one might read from your answer).
Apr
2
comment PINsentry PRNG and Bank Cards
That device is just a keyboard + screen extension for your card, the calculations are happening in the card.
Feb
12
awarded  Yearling
Jan
27
comment XKCD #936: Short complex password, or long dictionary passphrase?
For your password database, you should use a salt anyway, so rainbow tables are of no use.
Jan
4
comment Shouldn't GPG key fetching use a secure connection?
@humanityANDpeace In the case where there is no trusted path to (the key of) the sender of your message, you can't even trust that the message is really from this person. (The same is valid for encryption keys, with sender → receiver.) Anyone can upload a key with any name to the key server, and anyone else can express trust to this key, whether or not the connection is secured by TLS. The encrypted version of the protocol is there so nobody (other than the keyserver) knows which keys you request, I suppose.
Dec
22
comment Is my developer's home-brew password security right or wrong, and why?
I think the reason for the shuffling is to make the algorithm different from anything an attacker (who doesn't know the algorithm) expects. Using a application-specific secret salt input (aka "pepper") has this same effect and is more reliable.
Nov
19
comment How is the available entropy in /dev/random calculated (or estimated)?
I migrated your question here from cryptography Stack Exchange, because it seemed to be less about the cryptographic algorithms, and more about entropy collection. Please register your account here and on Crypto SE so you can gain possession of your question, comment and accept an answer.
Nov
19
revised How is the available entropy in /dev/random calculated (or estimated)?
edited tags
Nov
4
comment What is SHA-3 and why did we change it?
So you can use it when you have a hardware implementation in your server, I suppose.
Oct
8
revised How to protect encryption key while application is using it
edited tags
Oct
7
revised Using Elliptic Curve Cryptography
inline the diagram image
Oct
7
suggested suggested edit on Using Elliptic Curve Cryptography
Sep
2
comment Is this login authentication safe?
What is your goal? Do you want to let only people play who have a user account (i.e. a valid user name/password combination)? Also, how does the "login" relates to the rest of your session?
Aug
14
awarded  Caucus
Jun
29
comment How do I protect user data at rest?
@DavidSchwartz The point is that (a) the data stored at the server (the "public key") is not sufficient to authenticate against this server, and (b) you don't transfer the password (or "minimum needed to authenticate") to the server, i.e. no "using plain text password everywhere else". Also, the "public key" is a kind of salted hash.
Jun
29
comment How do I protect user data at rest?
@DavidSchwartz: Have a look at the SRP protocol as an example on how to store a password in hashed form and still don't have to send it in plain over the wire for checking.