User fgrieu

157 votes

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How big an RSA key is considered secure today?

answered Mar 3, 2012 at 11:29

129 votes

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If WhatsApp cannot read our message, how can the media forwarding happen in an instant?

answered Apr 18, 2018 at 6:25

73 votes

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Impacts of not using RSA exponent of 65537

answered Jul 1, 2012 at 10:49

67 votes

How can I make sure non-open source programs are really using end-to-end encryption?

answered Apr 8, 2020 at 7:12

61 votes

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Is the software that uses PGP broken, or is it PGP itself?

answered May 14, 2018 at 18:17

58 votes

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Why we can't implement AES 512 key size?

answered Nov 14, 2014 at 17:57

55 votes

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Cracking RSA (or other algorithms) manually by a savant

answered Jul 20, 2021 at 11:43

54 votes

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"SHA-256" vs "any 256 bits of SHA-512", which is more secure?

answered Jul 6, 2012 at 12:34

53 votes

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Is it bad to expose the public key?

answered Jun 18, 2017 at 15:05

52 votes

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Largest integer factored by Shor's algorithm?

answered Jun 5, 2018 at 9:08

50 votes

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Can you use memory errors as a source of randomness for cryptography?

answered Nov 7, 2017 at 22:26

47 votes

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How was the special DES key 0E329232EA6D0D73 found?

answered Jul 7, 2016 at 11:17

43 votes

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Does RSA work for any message M?

answered Oct 20, 2011 at 20:02

43 votes

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Is 80 bits of key size considered safe against brute force attacks?

answered Feb 3, 2014 at 17:40

42 votes

What size should the HMAC key be with SHA-256?

answered Apr 26, 2016 at 15:15

40 votes

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What makes Quantum Cryptography secure?

answered Sep 5, 2017 at 6:30

40 votes

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Is there a string that's hash is equal to itself?

answered Oct 6, 2014 at 14:15

40 votes

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Why is PuTTYgen-created RSA public exponent(e) not in {3,17,65537}?

answered Nov 25, 2015 at 16:10

39 votes

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What is a Pedersen commitment?

answered Nov 30, 2018 at 14:57

39 votes

Why can't I reverse a hash to a possible input?

answered Nov 11, 2015 at 11:16

39 votes

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Why is HMAC-SHA1 still considered secure?

answered Jun 25, 2015 at 10:33

37 votes

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Why is the Keyspace of a Substitution Cipher not 2^26 but 2^88

answered Jan 9, 2020 at 14:01

37 votes

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Why is plain-hash-then-encrypt not a secure MAC?

answered May 28, 2014 at 5:46

36 votes

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Why should I use an Initialization Vector (IV) when I have unique keys?

answered Jun 6, 2013 at 3:28

36 votes

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What are the odds of collisions for a hash function with 256-bit output?

answered Aug 27, 2016 at 19:01

36 votes

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How are the functions used in cryptographic hash functions chosen?

answered Nov 6, 2016 at 18:00

36 votes

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Is it safe to create a public ID by hashing a private key?

answered Aug 27 at 8:23

35 votes

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How can C rand() be exploited if a secure seed is used?

answered Oct 4, 2017 at 12:12

34 votes

Why is FIPS 140-2 compliance controversial?

answered Nov 22, 2021 at 12:31

34 votes

How come Public key cryptography wasn't discovered earlier?

answered May 25, 2018 at 9:43

Stack Exchange Network

2,343 Answers

How big an RSA key is considered secure today?

If WhatsApp cannot read our message, how can the media forwarding happen in an instant?

Impacts of not using RSA exponent of 65537

How can I make sure non-open source programs are really using end-to-end encryption?

Is the software that uses PGP broken, or is it PGP itself?

Why we can't implement AES 512 key size?

Cracking RSA (or other algorithms) manually by a savant

"SHA-256" vs "any 256 bits of SHA-512", which is more secure?

Is it bad to expose the public key?

Largest integer factored by Shor's algorithm?

Can you use memory errors as a source of randomness for cryptography?

How was the special DES key 0E329232EA6D0D73 found?

Does RSA work for any message M?

Is 80 bits of key size considered safe against brute force attacks?

What size should the HMAC key be with SHA-256?

What makes Quantum Cryptography secure?

Is there a string that's hash is equal to itself?

Why is PuTTYgen-created RSA public exponent(e) not in {3,17,65537}?

What is a Pedersen commitment?

Why can't I reverse a hash to a possible input?

Why is HMAC-SHA1 still considered secure?

Why is the Keyspace of a Substitution Cipher not 2^26 but 2^88

Why is plain-hash-then-encrypt not a secure MAC?

Why should I use an Initialization Vector (IV) when I have unique keys?

What are the odds of collisions for a hash function with 256-bit output?

How are the functions used in cryptographic hash functions chosen?

Is it safe to create a public ID by hashing a private key?

How can C rand() be exploited if a secure seed is used?

Why is FIPS 140-2 compliance controversial?

How come Public key cryptography wasn't discovered earlier?