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Jul
3
comment Does XTS provide random write access?
@elisae__ The attacker learns which blocks (at the same position) changed between versions. If blocks consist a single bit (xor based streamciphers, including CTR mode), they learn which bits are identical, which is often enough to recover the message. If you use AES-XTS they learn which 16 byte blocks are identical. If you use some kind of wide block cipher construction to get 4096 byte blocks, they only learn if such a large block changed. But since you need to rewrite a whole block at once, larger blocks limit random access operations.
Jul
3
revised Does XTS provide random write access?
added 307 characters in body
Jul
3
comment Can passwords be stored securely so that a similarity comparison can be made?
But it doesn't prevent somebody from alternating between two dissimilar passwords.
Jul
3
reviewed No Action Needed Can passwords be stored securely so that a similarity comparison can be made?
Jul
3
comment Can passwords be stored securely so that a similarity comparison can be made?
Of course this only works for the immediately prior password and not for comparing with older passwords.
Jul
3
comment Does XTS provide random write access?
How are you protecting integrity? A merkle tree of hashes/MACs?
Jul
3
answered Does XTS provide random write access?
Jul
2
comment How often does RSA-OAEP have a leading zero?
@TBridges42 Depends on the most significant byte of the public key. The probability should be approximately p(MSB(ciphertext)=0) = 1/MSB(public key).
Jul
2
reviewed Reject Is One Time Pad something like this?
Jul
1
comment How often does RSA-OAEP have a leading zero?
If this is about the most significant byte of the ciphertext being zero, it's possible. Padding affects the plaintext.
Jul
1
reviewed No Action Needed Is this client-side password hash scheme secure?
Jul
1
reviewed Reviewed Is this client-side password hash scheme secure?
Jul
1
comment Is this client-side password hash scheme secure?
For code spanning several lines, I recommend indenting it with 4 spaces, instead of using a <code> html tag.
Jul
1
revised Is this client-side password hash scheme secure?
deleted 10 characters in body
Jul
1
awarded  Revival
Jul
1
reviewed No Action Needed Does authenticated encryption add any protection to a signed digital envelope?
Jul
1
reviewed No Action Needed ElGamal scheme attack when one message is known and ciphertexts are intercepted
Jul
1
comment Building a combined encryption scheme from two encryption schemes that's secure if at least on of them is secure
@Gordon While you can't delete this question, you can contact stackexchange asking to disassociate it from your account.
Jul
1
comment How much computing resource is required to brute-force RSA?
Related question: How many RSA keys before a collision?
Jul
1
revised “123456” and “password” as crack standards
deleted 23 characters in body