1,129 reputation
11121
bio website samuelkerr.com
location United States
age 26
visits member for 3 years, 3 months
seen Oct 28 at 13:50

May
8
comment What are some restrictions when converting Montgomery Curves into Weierstrass Curves?
Another relevant point to this answer is that after remapping to Weierstrass form, the x=9 coordinate must also be remapped with the same change of variables.
Feb
24
comment Does a cofactor of an elliptic curve have to be an integer?
tylo, very good point. I'd give you an upvote if you made an answer.
Feb
7
comment What are some restrictions when converting Montgomery Curves into Weierstrass Curves?
You're right, thanks for the point!
Sep
2
comment Where can I double check my elliptic curve results?
Clearly, my problem is with doing basic arithmetic in my head sigh
Jul
20
comment How difficult is it to find the “pre-image” of a block cipher?
Or better yet, what about the scenario where $M_1$ and $M_2$ are fixed.
Jul
20
comment How difficult is it to find the “pre-image” of a block cipher?
@Thomas I guess I'm asking is there a way to do this without enumerating the entire key space...
Jul
16
comment How can I use asymmetric encryption, such as RSA, to encrypt an arbitrary length of plaintext?
While I do agree that the proposed situation is non-standard, simply saying to use AES I believe is incorrect, since it assumes you can securely distribute keys. Also, what do you mean it exposes weaknesses in the ciphers themselves?
Jun
19
comment Is it possible to use the RSA algorithm, or a variant, for software licensing?
Just a thought, why not pay for or license a license manager? You want to focus on your application, not making sure the license manager is secure and functioning.
Jul
15
comment Is it possible to derive the encryption method from encrypted text?
Alternatively, if you determine with LESS than 1/2, you can also consider it broken. Simply pick the opposite of whatever your algorithm says.
Jul
13
comment How can I generate large prime numbers for RSA?
+1 for mentioning FIPS, which is different than what most implementations use.
Jul
13
comment What are the practical differences between 256-bit, 192-bit, and 128-bit AES encryption?
There are actual several attacks against AES, reducing time below 2^length. The attacks can be done in 2^119, 2^176, and 2^200 respectively. schneier.com/blog/archives/2009/07/another_new_aes.html
Jul
12
comment How can a random salt for a hash function work in practice?
You could also think of this as a first preimage attack. This attack is that given a hash h, find a message m where H(m) = h. If the salt was known, this would simply reduce to H(m | salt) = h. Assuming you have a secure hash algorithm, it should be able to resist this first preimage attack.
Jul
12
comment How can a random salt for a hash function work in practice?
That's not true. Without the salt, the attacker would be required to execute a brute force attack. With the salt, the attacker will still need a brute force attack. The difference is, with salt the attacker cannot pre-compute many easy hashes (of 'dog', 'password', etc.) but rather must re-compute the entire hash key space ('dog_kaskd2e','password_kaskd2e', etc).