Talk:Key size

message: 1988 January 22
http://www.itl.nist.gov/fipspubs/fip46-2.htm
States in section 15
"no technique other than trying all possible keys using known input and output for the DES will guarantee finding the chosen key. As there are over 70,000,000,000,000,000 (seventy quadrillion) possible keys of 56 bits, the feasibility of deriving a particular key in this way is extremely unlikely in typical threat environments. "
Biofuel (talk) 06:40, 14 December 2012 (UTC)
replies: text: That may have been true in 1988, it's not true now. --agr (talk) 11:49, 14 December 2012 (UTC)
replies: text:  Well, the statement in question "... was thought[who?] to be sufficient ..." is about the security of DES when it was released. The reference given by the OP still judges the security of DES as sufficient (for typical applications) even 11 years after release. So, yes it is still true that in 1988 NBS rated the security of DES as sufficient. 178.195.225.28 (talk) 10:02, 15 December 2012 (UTC)
thread_title:  [who?] key size question 

message: One of the asymmetric algorithm types, elliptic curve cryptography, or ECC, appears to be secure with shorter keys than those needed by other asymmetric key algorithms. NIST guidelines state that ECC keys should be twice the length of equivalent strength symmetric key algorithms. So, for example, a 224-bit ECC key would have roughly the same strength as a 112-bit symmetric key.
If ECC is "secure with shorter keys" then the NIST recommendation would be half the length, and a 112 bit ECC key would be roughly as secure as 224 symmetric (it's given the other way around).
In other words this section should read as follows, either of these versions:
:* One of the asymmetric algorithm types, elliptic curve cryptography, or ECC, appears to be secure with longer keys than those needed by other asymmetric key algorithms. NIST guidelines state that ECC keys should be twice the length of equivalent strength symmetric key algorithms. So, for example, a 224-bit ECC key would have roughly the same strength as a 112-bit symmetric key.
:* One of the asymmetric algorithm types, elliptic curve cryptography, or ECC, appears to be secure with shorter keys than those needed by other asymmetric key algorithms. NIST guidelines state that ECC keys can be half the length of equivalent strength symmetric key algorithms. So, for example, a 112-bit ECC key would have roughly the same strength as a 224-bit symmetric key.
Fix? FT2 (Talk | email) 00:29, 30 May 2007 (UTC)
replies: text: Very late reply, but anyway... you misread the paragraph. It says "ECC appears to be secure with shorter keys than those needed by other asymmetric key algorithms [...] So, for example, a 224-bit ECC key would have roughly the same strength as a 112-bit symmetric key." ECC needs shorter keys than (say) RSA, but longer than (say) AES. -- BenRG (talk) 21:12, 28 January 2008 (UTC)
thread_title:  Error in article, needs fixing 

message: I am not sufficiently expert to write a suitable section, but should there be a section explaining that most current encryption algorithms are vulnerable to quantum computing techniques, when and if they are sufficiently mature? I would suggest that this branch of computing is much nearer providing routine cracking of present day encryption techniques than Moore's Law would indicate. Of course, we do not know what is happening inside organizations such as GCHQ and NSA! --APRCooper (talk) 14:26, 28 February 2008 (UTC)
replies: text: I added a section. -- BenRG (talk) 13:36, 5 March 2008 (UTC)

text: Thanks! --APRCooper (talk) 17:25, 7 March 2008 (UTC)
thread_title:  Quantum Computing? 

message: It is claimed that:
:The Finite Field Diffie-Hellman algorithm has roughly the same key strength as RSA for the same key sizes. The work factor for breaking Diffie-Hellman is based on the discrete logarithm problem, which is related to the integer factorization problem on which RSA's strength is based. Thus, a 3072-bit Diffie-Hellman key has about the same strength as a 3072-bit RSA key.
:
Really? Discrete logarithm is a harder problem than factoring.  — Preceding unsigned comment added by Kuroyama (talk • contribs) 01:40, 21 February 2013 (UTC)
replies: text: not in finite fields. --MarioS (talk) 11:55, 3 June 2013 (UTC)
thread_title:  Diffie-Hellman key strength 

message: What is meant by "sufficiently large" could a "sufficiently large" conventional computer do the job? 87.112.9.121 (talk) 19:23, 13 March 2014 (UTC)
thread_title:  "if sufficiently large quantum computers capable of running Shor's algorithm become available" 

message: The sentence
:Since longer symmetric keys require exponentially more work to brute force search, a sufficiently long symmetric key makes this line of attack impractical. 
Shouldn't this be "...longer asymmetric keys..." and "...long asymmetric keys..."? Enotdetcelfer (talk) 04:48, 12 February 2019 (UTC)
thread_title:  Mistake? Symmetric vs. Asymmetric 

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thread_title:  External links modified 

message: The article currently says: As of 2003 RSA Security claims that 1024-bit RSA keys are equivalent in strength to 80-bit symmetric keys, 2048-bit RSA keys to 112-bit symmetric keys and 3072-bit RSA keys to 128-bit symmetric keys.[14] RSA claims that 1024-bit keys are likely to become crackable some time between 2006 and 2010 and that 2048-bit keys are sufficient until 2030.[14] An RSA key length of 3072 bits should be used if security is required beyond 2030.[15] NIST key management guidelines further suggest that 15360-bit RSA keys are equivalent in strength to 256-bit symmetric keys.[16]
The reference is to a 2003 analysis. Since we're now in 2017, it seems that we should know whether 1024-bit keys actually did become crackable. So, two questions: is there a tag for Wikipedia to mark predictions like this, like a DIDTHISCOMETRUE template? And, second: did this actually come true? --ESP (talk) 18:30, 24 November 2017 (UTC)
replies: text: They did not become crackable. The best-known public attack in 2023 is still under 829 bits (from 2020). Paulehoffman (talk) 01:52, 11 February 2023 (UTC)
thread_title:  RSA key strength 

message: The text in the introduction indicates that a new attack reduced the strength of TripleDES after it was designed. That is not true: the meet-in-the-middle attack was known before TripleDES was created. The design goal for TripleDES was 112 bits. I would like to change the intro to remove TripleDES but instead insert RSA, where the NFS attacks were indeed a surprise. Paulehoffman (talk) 16:08, 11 February 2023 (UTC)
thread_title:  TripleDES was known to have 112 bits of strength from the start