[cryptography] Dual_EC_DRBG was cooked, but not AES?
temp at synernet.com
Sun Sep 22 09:05:06 EDT 2013
The Snowden revelations describe several methods by which NSA committed kleptography, caused compliance by hardware makers and influenced standards.
Why has AES escaped general suspicion? Are we to believe that NIST tested, selected, endorsed and promulgated an algorithm that was immune to NSA's toolset, without NSA participation and approval? NSA involvement in DES is known, but we await cryptanalysis or Snowdenesque revelations before having skepticism about AES?
"On 17 March 1975, the proposed DES was published in the Federal Register. Public comments were requested, and in the following year two open workshops were held to discuss the proposed standard. There was some criticism from various parties, including from public-key cryptography pioneers Martin Hellman and Whitfield Diffie, citing a shortened key length and the mysterious "S-boxes" as evidence of improper interference from the NSA. The suspicion was that the algorithm had been covertly weakened by the intelligence agency so that they — but no-one else — could easily read encrypted messages. Alan Konheim (one of the designers of DES) commented, "We sent the S-boxes off to Washington. They came back and were all different." The United States Senate Select Committee on Intelligence reviewed the NSA's actions to determine whether there had been any improper involvement. In the unclassified summary of their findings, published in 1978, the Committee wrote:
In the development of DES, NSA convinced IBM that a reduced key size was sufficient; indirectly assisted in the development of the S-box structures; and certified that the final DES algorithm was, to the best of their knowledge, free from any statistical or mathematical weakness.
However, it also found that
NSA did not tamper with the design of the algorithm in any way. IBM invented and designed the algorithm, made all pertinent decisions regarding it, and concurred that the agreed upon key size was more than adequate for all commercial applications for which the DES was intended."
"On September 10 2013, The New York Times wrote that "internal memos leaked by a former N.S.A. contractor, Edward Snowden, suggest that the N.S.A. generated one of the random number generators used in a 2006 N.I.S.T. standard — called the Dual EC DRBG standard — which contains a backdoor for the NSA." On September 10 2013, The NIST director released a statement, saying that "NIST would not deliberately weaken a cryptographic standard.""
"A major American computer security company has told thousands of customers to stop using an encryption system that relies on a mathematical formula developed by the National Security Agency (NSA).
RSA, the security arm of the storage company EMC, sent an email to customers telling them that the default random number generator in a toolkit for developers used a weak formula, and they should switch to one of the other formulas in the product.
The abrupt warning is the latest fallout from the huge intelligence disclosures by the whistleblower Edward Snowden about the extent of surveillance and the debasement of encryption by the NSA.
Last week, the New York Times reported that Snowden's cache of documents from his time working for an NSA contractor showed that the agency used its public participation in the process for setting voluntary cryptography standards, run by the government's National Institute of Standards (NIST) and Technology, to push for a formula it knew it could break. Soon after that revelation, the NIST began advising against the use of one of its cryptographic standards and, having accepted the NSA proposal in 2006 as one of four systems acceptable for government use, said it would reconsider that inclusion in the wake of questions about its security."
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