User Thomas Pornin - Cryptography Stack Exchange

Thomas Pornin

Member for 12 years, 5 months
Last seen this week

bolet.org/~pornin
Quebec City, Canada

557 Answers

Score Activity Newest

162 votes

Accepted

What is the "Random Oracle Model" and why is it controversial?

answered Sep 30, 2011 at 16:58

160 votes

Accepted

Why is elliptic curve cryptography not widely used, compared to RSA?

answered Nov 15, 2011 at 15:29

153 votes

Should we MAC-then-encrypt or encrypt-then-MAC?

answered Jul 21, 2011 at 13:16

127 votes

How much would it cost in U.S. dollars to brute-force a 256-bit key in a year?

answered Nov 8, 2011 at 13:32

118 votes

Accepted

Can you explain Bleichenbacher's CCA attack on PKCS#1 v1.5?

answered Jan 3, 2014 at 15:53

108 votes

Accepted

How should I calculate the entropy of a password?

answered Aug 11, 2011 at 12:32

89 votes

Best way to reduce chance of hash collisions: Multiple hashes, or larger hash?

answered Nov 11, 2011 at 16:14

85 votes

Should we trust the NIST-recommended ECC parameters?

answered Sep 9, 2013 at 18:15

84 votes

Accepted

Understanding the length extension attack

answered Oct 7, 2012 at 16:46

84 votes

Accepted

What are the practical differences between 256-bit, 192-bit, and 128-bit AES encryption?

answered Jul 12, 2011 at 19:58

81 votes

Accepted

Why doesn't SSH use TLS?

answered Jun 24, 2018 at 12:52

81 votes

Accepted

Is AES-256 weaker than 192 and 128 bit versions?

answered Oct 20, 2012 at 0:33

75 votes

Layman's explanation of encryption backdoors

answered Feb 17, 2016 at 14:30

72 votes

What is bignum-free RSA?

answered Jun 7, 2018 at 12:44

67 votes

Cryptography algorithms that take longer to solve on a GPU than a CPU

answered Oct 1, 2017 at 21:38

60 votes

Guarding against cryptanalytic breakthroughs: combining multiple hash functions

answered Jul 29, 2011 at 17:25

56 votes

Accepted

What are the implications of the new alleged key recovery attack preprint on SIMON?

answered May 11, 2019 at 13:58

56 votes

Accepted

How secure is SHA1? What are the chances of a real exploit?

answered Jun 14, 2017 at 16:52

56 votes

Accepted

How to check that you got the right key when brute forcing an encryption?

answered Feb 28, 2016 at 19:53

56 votes

Accepted

What are the benefits of the two permutation tables in DES?

answered Jul 12, 2011 at 18:48

50 votes

Accepted

What is the difference between CSPRNG and PRNG?

answered Dec 18, 2013 at 20:23

49 votes

Accepted

How can one securely generate an asymmetric key pair from a short passphrase?

answered Jan 14, 2012 at 22:14

47 votes

Accepted

Is there an AES identity key?

answered Apr 12, 2016 at 17:58

47 votes

Google is using RC4, but isn't RC4 considered unsafe?

answered Sep 29, 2011 at 12:44

44 votes

Accepted

Can a hard drive store clear text data that is physically impossible to retrieve?

answered Feb 6, 2018 at 21:13

43 votes

Accepted

Is it feasible to build an index of prime factors?

answered Oct 21, 2011 at 14:02

43 votes

Accepted

How does asymmetric encryption work?

answered Aug 3, 2011 at 13:12

43 votes

Accepted

AES CBC mode or AES CTR mode recommended?

answered Jan 19, 2013 at 14:13

41 votes

Why is SHA-3 robust against Length-Extension Attacks?

answered Sep 25, 2018 at 19:24

41 votes

Accepted

If you hashed a hash an infinite number of times would you end up with a unique hash?

answered Apr 25, 2015 at 20:52

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