Reputation
3,637
Top tag
Next privilege 5,000 Rep.
Approve tag wiki edits
Badges
8 23
Newest
 Nice Answer
Impact
~83k people reached

Sep
3
comment Elliptic Curve Cryptography Encryption Results
RSA does not involve any randomness, but it is trivially breakable (if used in the context involved here). Say I send you a message in plaintext, "Should we attack? Respond 'yes' or 'no' encrypting with RSA." This is trivially breakable, you can just trial encrypt both the 'yes' and the 'no'. This is one of the reasons RSA is not used alone. A public key algorithm that operates on short plaintext (which is what we're talking about here) must involve some randomness or it's trivially breakable by trial encryption.
Sep
1
answered Elliptic Curve Cryptography Encryption Results
Aug
28
comment Should I delete cryptographic data from memory?
What are you trying to prevent exactly? Presumably an "attacker" who had access to the machine's memory would thereby be entitled to the data the machine had processed. And if your model is that an attacker may have control over the machine while it's processing the data, erasing it later won't help. Are you trying to protect against sensitive data in swap or core dumps?
Aug
13
awarded  Yearling
Jul
31
awarded  Nice Answer
Jul
4
awarded  Tag Editor
Jul
4
revised length-extension wiki description
The MAC/hash does change, it just changes in a way that allows the attacker to maintain its validity.
Jul
4
suggested approved edit on length-extension tag wiki
Jul
4
awarded  Custodian
Jul
4
reviewed Approve length-extension tag wiki
Jul
4
reviewed Approve length-extension tag wiki excerpt
Jul
4
comment Cryptographic Challenge: How to Say Something Confidentially to Snowden?
You must have some way, in principle, to identify Snowden. If you have such a way, we must know what it is. If you do not, then it is provably impossible -- anything that identifies the Snowden you have in mind could also identify someone else.
Jun
21
comment Is there a hash function which has no collisions?
@improv32: Just use any encryption scheme you like with a key much shorter than the data. (You can easily remove this requirement if needed.) To later prove you had the data earlier, release the key you encrypted it with.
May
12
awarded  Good Answer
Apr
27
comment How can a key pair be derived from an arbitrary hash?
Yes, it basically is.
Apr
27
comment Is it possible to determine a PGP public key from encrypted data?
The decrypted content is of no help accomplishing this task. But he can trivially do it because the PGP file contains the ID of the key needed to decrypt it.
Apr
27
answered How can a key pair be derived from an arbitrary hash?
Apr
14
comment How to use salt if I am sending hashed password?
Step 3 is essential, do not skip it.
Apr
3
comment Is there a practical security difference between XXX-bit encryption?
This is not quite true. Consider, for example, if the process of generating the secret key from the password is extraordinarily computation intensive. If it's, say, a billion times harder to test if a guess at the password is correct than it is to check if a guessed secret key is correct, that can effectively make the password 30 bits longer relative to the secret key.
Apr
1
comment Decrypt digital signature using RSA public key with openssl
How many bits is the RSA key you are using? "data greater than mod len" usually indicates either a "toy" key that doesn't have enough bits or an attempt to operate on the actual data where you should be operating on a hash.