Re: high-grade vs low-grade encryption with MD5 and DES
Hi, I never see 4096 bits keys used in the SSL transactions. I once see the key in the root CA in the natioanl PKI initiative in one country under very restrictive usage with customized application. I am just wondering if the market is moving to use such a longer bits key. -Kiyoshi Kiyoshi Watanabe Practicality : do not use 4096 bits server side private key. No, not even 2048. Key size larger than 1024 is not supported by those bollocky client browsers. Netscape and MSIE4 come to mind. Regards, Arthur Chan - Original Message - From: Dave Paris [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, August 11, 2003 07:34 PM Subject: RE: high-grade vs low-grade encryption with MD5 and DES The 5 minutes I mentioned doesn't implicitly refer to the amount of time needed to crack the ciphertext, but more the type of data and the amount of time it needs to be protected. A couple examples: Example 1: A password which will only work for the next ten minutes only needs to be protected by encryption capable of rendering the text sufficiently scrambled for that 10 minute duration. This might mean it would take an attacker 1 minute to obtain the ciphertext and get it into a state where it can be cryptanalyzed. Four or five minutes to determine the cipher used. Then the attacker is left with only 3 or 4 minutes to break the cipher if they need one minute to actually use the password. So, how strong do you need encryption in this case? Only long enough to hold out against a 3 to 4 minute attack. Example 2: A sealed court case which is mandated to be sealed for 20 years needs to be protected by a cipher capable of using a large enough keyspace to keep a sustained attack against the data at bay for that 20 years. Herein lies the challenge in the practical utilization of cryptography... how do we know what will protect data for 20 years? We don't. So we make educated guesses. We make compromizes. We use best-available. In the example of the password above, 56 bit DES would be a reasonable choice. It's fast, but weak - yet strong enough to keep that password encrypted for the two or three - heck, six, minutes it would be attacked. (this is not to say that one should use the weakest available cipher for any given problem set! 3DES, AES, or Blowfish would be a much better choice in any case.) In the example of the sealed court records, we're not worried about transaction speed or decryption speed so an asymmetric cipher capable of utilizing a 4096 bit (or larger!) private key is much more appropriate. Kind Regards, -dsp -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Arthur Chan Sent: Sunday, August 10, 2003 6:39 AM To: [EMAIL PROTECTED] Subject: Re: high-grade vs low-grade encryption with MD5 and DES This is really symptomatic of our industry, isn't it? We seen to be our own worse enemy. Back in 95, it took that French student days to crack the 40-bit codes. Now we are talking about minutes... its disheartening. Merde. I really wonder how some of those MS sites survive these days... - Original Message - From: Dave Paris [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, August 11, 2003 06:16 PM Subject: Re: high-grade vs low-grade encryption with MD5 and DES compromised is probably a poor word to use, pointlessly weak is more accurate. If you're going to use SSL and you're dealing with data that needs to be protected longer than 5 minutes, use 128bit SSL. -dsp On Sunday, Aug 10, 2003, at 02:25 US/Eastern, Arthur Chan wrote: Hi all. Verisign currently has a discount on both a high grade (128bits) SSL encrypted and a low grade (40bits) SSL encrypted certificates. The former is priced at US$895 and the latter at US$1395. I noticed some sites also present Verisign certificates with low-grade, 54-bits encryption from their Microsoft/IIS servers. However I cannot find a 54-bits certificate in www.verisign.com/products/site/commerce/index.html Is this 54-bits affair only for Microsoft / IIS ??? Is low-grade encryption with 40 and 54 bits considered compromised ??? Are there any finance/insurance industry standard requiring a 128 bits, high-grade encryption ??? __ Apache Interface to OpenSSL (mod_ssl) www.modssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager[EMAIL PROTECTED] __ Apache Interface to OpenSSL (mod_ssl) www.modssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager[EMAIL
RE: high-grade vs low-grade encryption with MD5 and DES
The 5 minutes I mentioned doesn't implicitly refer to the amount of time needed to crack the ciphertext, but more the type of data and the amount of time it needs to be protected. A couple examples: Example 1: A password which will only work for the next ten minutes only needs to be protected by encryption capable of rendering the text sufficiently scrambled for that 10 minute duration. This might mean it would take an attacker 1 minute to obtain the ciphertext and get it into a state where it can be cryptanalyzed. Four or five minutes to determine the cipher used. Then the attacker is left with only 3 or 4 minutes to break the cipher if they need one minute to actually use the password. So, how strong do you need encryption in this case? Only long enough to hold out against a 3 to 4 minute attack. Example 2: A sealed court case which is mandated to be sealed for 20 years needs to be protected by a cipher capable of using a large enough keyspace to keep a sustained attack against the data at bay for that 20 years. Herein lies the challenge in the practical utilization of cryptography... how do we know what will protect data for 20 years? We don't. So we make educated guesses. We make compromizes. We use best-available. In the example of the password above, 56 bit DES would be a reasonable choice. It's fast, but weak - yet strong enough to keep that password encrypted for the two or three - heck, six, minutes it would be attacked. (this is not to say that one should use the weakest available cipher for any given problem set! 3DES, AES, or Blowfish would be a much better choice in any case.) In the example of the sealed court records, we're not worried about transaction speed or decryption speed so an asymmetric cipher capable of utilizing a 4096 bit (or larger!) private key is much more appropriate. Kind Regards, -dsp -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Arthur Chan Sent: Sunday, August 10, 2003 6:39 AM To: [EMAIL PROTECTED] Subject: Re: high-grade vs low-grade encryption with MD5 and DES This is really symptomatic of our industry, isn't it? We seen to be our own worse enemy. Back in 95, it took that French student days to crack the 40-bit codes. Now we are talking about minutes... its disheartening. Merde. I really wonder how some of those MS sites survive these days... - Original Message - From: Dave Paris [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, August 11, 2003 06:16 PM Subject: Re: high-grade vs low-grade encryption with MD5 and DES compromised is probably a poor word to use, pointlessly weak is more accurate. If you're going to use SSL and you're dealing with data that needs to be protected longer than 5 minutes, use 128bit SSL. -dsp On Sunday, Aug 10, 2003, at 02:25 US/Eastern, Arthur Chan wrote: Hi all. Verisign currently has a discount on both a high grade (128bits) SSL encrypted and a low grade (40bits) SSL encrypted certificates. The former is priced at US$895 and the latter at US$1395. I noticed some sites also present Verisign certificates with low-grade, 54-bits encryption from their Microsoft/IIS servers. However I cannot find a 54-bits certificate in www.verisign.com/products/site/commerce/index.html Is this 54-bits affair only for Microsoft / IIS ??? Is low-grade encryption with 40 and 54 bits considered compromised ??? Are there any finance/insurance industry standard requiring a 128 bits, high-grade encryption ??? __ Apache Interface to OpenSSL (mod_ssl) www.modssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager[EMAIL PROTECTED] __ Apache Interface to OpenSSL (mod_ssl) www.modssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager[EMAIL PROTECTED] __ Apache Interface to OpenSSL (mod_ssl) www.modssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager[EMAIL PROTECTED] __ Apache Interface to OpenSSL (mod_ssl) www.modssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager[EMAIL PROTECTED]
RE: high-grade vs low-grade encryption with MD5 and DES
I wasn't [specifically] referring to SSL. In fact, the mere premise of passing data designated as must be protected for a 20 year timeframe over 128 bit SSL (with a 1024 bit client key) frightens me to the core. (If the encryption of this data was protecting *you* from [we'll go on a limb here and be dramatic] an crime organization with tens of millions of dollars to devote to discovering who turned them in to the Feds, would *you* want it sent over a 1024 bit SSL link?!) *THIS* is what's really wrong with the industry - we have people using technology in inappropriate situations. Too many who DO understand how to use it appropriately with the responsibilities, restrictions, and caveats that come with that understanding are either unable or unwilling to convince those in the position of final decision maker of just how WRONG certain applications/implementations actually are. Bottom line, if the available protocols application cannot support the data protection requirements - DO NOT send the data over that link. For a baseline dissertation on key lengths for symmetric and asymmetric ciphers, please see: http://www.giac.org/practical/gsec/Lorraine_Williams_GSEC.pdf Additionally, RSA currently recommends 2048 bit keys for extremely valuable keys. My gut says that knowing about devices like TWIRL, et al. make 2048 bit keys risky for long-term protection because God only knows what devices we *don't* know about. -dsp -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Arthur Chan Sent: Sunday, August 10, 2003 7:52 AM To: [EMAIL PROTECTED] Subject: Re: high-grade vs low-grade encryption with MD5 and DES Practicality : do not use 4096 bits server side private key. No, not even 2048. Key size larger than 1024 is not supported by those bollocky client browsers. Netscape and MSIE4 come to mind. Regards, Arthur Chan - Original Message - From: Dave Paris [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, August 11, 2003 07:34 PM Subject: RE: high-grade vs low-grade encryption with MD5 and DES The 5 minutes I mentioned doesn't implicitly refer to the amount of time needed to crack the ciphertext, but more the type of data and the amount of time it needs to be protected. [...] Example 2: A sealed court case which is mandated to be sealed for 20 years needs to be protected by a cipher capable of using a large enough keyspace to keep a sustained attack against the data at bay for that 20 years. Herein lies the challenge in the practical utilization of cryptography... how do we know what will protect data for 20 years? We don't. So we make educated guesses. We make compromizes. We use best-available. In the example of the password above, 56 bit DES would be a reasonable choice. It's fast, but weak - yet strong enough to keep that password encrypted for the two or three - heck, six, minutes it would be attacked. (this is not to say that one should use the weakest available cipher for any given problem set! 3DES, AES, or Blowfish would be a much better choice in any case.) In the example of the sealed court records, we're not worried about transaction speed or decryption speed so an asymmetric cipher capable of utilizing a 4096 bit (or larger!) private key is much more appropriate. [...] __ Apache Interface to OpenSSL (mod_ssl) www.modssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager[EMAIL PROTECTED]
Re: high-grade vs low-grade encryption with MD5 and DES
Hi Yoshi. I have been looking around and haven't seen 4096 in use either. I think most companies have settled for the standard by default ie 1024/128 and it would be a lot of work to change that. What do they do under those circumstances ? Revoke the old certificate and issue new one ? You can do your own survey, simply throw up the log-on screen for the major banks (and second tier ones), then look at their certificates. They all have 1024/128. I can't see a long live for 1024/128, maybe a few more years. Something is bound to happen. Also, I doubt whether it is practical, seeing how some (slightly) older browsers cannot handle that. Arthur - Original Message - From: Kiyoshi Watanabe [EMAIL PROTECTED] To: [EMAIL PROTECTED]; [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Sent: Monday, August 11, 2003 08:39 PM Subject: Re: high-grade vs low-grade encryption with MD5 and DES Hi, I never see 4096 bits keys used in the SSL transactions. I once see the key in the root CA in the natioanl PKI initiative in one country under very restrictive usage with customized application. I am just wondering if the market is moving to use such a longer bits key. -Kiyoshi Kiyoshi Watanabe Practicality : do not use 4096 bits server side private key. No, not even 2048. Key size larger than 1024 is not supported by those bollocky client browsers. Netscape and MSIE4 come to mind. Regards, Arthur Chan - Original Message - From: Dave Paris [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, August 11, 2003 07:34 PM Subject: RE: high-grade vs low-grade encryption with MD5 and DES The 5 minutes I mentioned doesn't implicitly refer to the amount of time needed to crack the ciphertext, but more the type of data and the amount of time it needs to be protected. A couple examples: Example 1: A password which will only work for the next ten minutes only needs to be protected by encryption capable of rendering the text sufficiently scrambled for that 10 minute duration. This might mean it would take an attacker 1 minute to obtain the ciphertext and get it into a state where it can be cryptanalyzed. Four or five minutes to determine the cipher used. Then the attacker is left with only 3 or 4 minutes to break the cipher if they need one minute to actually use the password. So, how strong do you need encryption in this case? Only long enough to hold out against a 3 to 4 minute attack. Example 2: A sealed court case which is mandated to be sealed for 20 years needs to be protected by a cipher capable of using a large enough keyspace to keep a sustained attack against the data at bay for that 20 years. Herein lies the challenge in the practical utilization of cryptography... how do we know what will protect data for 20 years? We don't. So we make educated guesses. We make compromizes. We use best-available. In the example of the password above, 56 bit DES would be a reasonable choice. It's fast, but weak - yet strong enough to keep that password encrypted for the two or three - heck, six, minutes it would be attacked. (this is not to say that one should use the weakest available cipher for any given problem set! 3DES, AES, or Blowfish would be a much better choice in any case.) In the example of the sealed court records, we're not worried about transaction speed or decryption speed so an asymmetric cipher capable of utilizing a 4096 bit (or larger!) private key is much more appropriate. Kind Regards, -dsp -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Arthur Chan Sent: Sunday, August 10, 2003 6:39 AM To: [EMAIL PROTECTED] Subject: Re: high-grade vs low-grade encryption with MD5 and DES This is really symptomatic of our industry, isn't it? We seen to be our own worse enemy. Back in 95, it took that French student days to crack the 40-bit codes. Now we are talking about minutes... its disheartening. Merde. I really wonder how some of those MS sites survive these days... - Original Message - From: Dave Paris [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, August 11, 2003 06:16 PM Subject: Re: high-grade vs low-grade encryption with MD5 and DES compromised is probably a poor word to use, pointlessly weak is more accurate. If you're going to use SSL and you're dealing with data that needs to be protected longer than 5 minutes, use 128bit SSL. -dsp On Sunday, Aug 10, 2003, at 02:25 US/Eastern, Arthur Chan wrote: Hi all. Verisign currently has a discount on both a high grade (128bits) SSL encrypted and a low grade (40bits) SSL encrypted certificates. The former is priced at US$895 and the latter at US$1395. I noticed some sites also present Verisign certificates with low-grade
Re: high-grade vs low-grade encryption with MD5 and DES
This is really symptomatic of our industry, isn't it? We seen to be our own worse enemy. Back in 95, it took that French student days to crack the 40-bit codes. Now we are talking about minutes... its disheartening. Merde. I really wonder how some of those MS sites survive these days... - Original Message - From: Dave Paris [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, August 11, 2003 06:16 PM Subject: Re: high-grade vs low-grade encryption with MD5 and DES compromised is probably a poor word to use, pointlessly weak is more accurate. If you're going to use SSL and you're dealing with data that needs to be protected longer than 5 minutes, use 128bit SSL. -dsp On Sunday, Aug 10, 2003, at 02:25 US/Eastern, Arthur Chan wrote: Hi all. Verisign currently has a discount on both a high grade (128bits) SSL encrypted and a low grade (40bits) SSL encrypted certificates. The former is priced at US$895 and the latter at US$1395. I noticed some sites also present Verisign certificates with low-grade, 54-bits encryption from their Microsoft/IIS servers. However I cannot find a 54-bits certificate in www.verisign.com/products/site/commerce/index.html Is this 54-bits affair only for Microsoft / IIS ??? Is low-grade encryption with 40 and 54 bits considered compromised ??? Are there any finance/insurance industry standard requiring a 128 bits, high-grade encryption ??? __ Apache Interface to OpenSSL (mod_ssl) www.modssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager[EMAIL PROTECTED] __ Apache Interface to OpenSSL (mod_ssl) www.modssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager[EMAIL PROTECTED] __ Apache Interface to OpenSSL (mod_ssl) www.modssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager[EMAIL PROTECTED]
Re: high-grade vs low-grade encryption with MD5 and DES
Practicality : do not use 4096 bits server side private key. No, not even 2048. Key size larger than 1024 is not supported by those bollocky client browsers. Netscape and MSIE4 come to mind. Regards, Arthur Chan - Original Message - From: Dave Paris [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, August 11, 2003 07:34 PM Subject: RE: high-grade vs low-grade encryption with MD5 and DES The 5 minutes I mentioned doesn't implicitly refer to the amount of time needed to crack the ciphertext, but more the type of data and the amount of time it needs to be protected. A couple examples: Example 1: A password which will only work for the next ten minutes only needs to be protected by encryption capable of rendering the text sufficiently scrambled for that 10 minute duration. This might mean it would take an attacker 1 minute to obtain the ciphertext and get it into a state where it can be cryptanalyzed. Four or five minutes to determine the cipher used. Then the attacker is left with only 3 or 4 minutes to break the cipher if they need one minute to actually use the password. So, how strong do you need encryption in this case? Only long enough to hold out against a 3 to 4 minute attack. Example 2: A sealed court case which is mandated to be sealed for 20 years needs to be protected by a cipher capable of using a large enough keyspace to keep a sustained attack against the data at bay for that 20 years. Herein lies the challenge in the practical utilization of cryptography... how do we know what will protect data for 20 years? We don't. So we make educated guesses. We make compromizes. We use best-available. In the example of the password above, 56 bit DES would be a reasonable choice. It's fast, but weak - yet strong enough to keep that password encrypted for the two or three - heck, six, minutes it would be attacked. (this is not to say that one should use the weakest available cipher for any given problem set! 3DES, AES, or Blowfish would be a much better choice in any case.) In the example of the sealed court records, we're not worried about transaction speed or decryption speed so an asymmetric cipher capable of utilizing a 4096 bit (or larger!) private key is much more appropriate. Kind Regards, -dsp -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Arthur Chan Sent: Sunday, August 10, 2003 6:39 AM To: [EMAIL PROTECTED] Subject: Re: high-grade vs low-grade encryption with MD5 and DES This is really symptomatic of our industry, isn't it? We seen to be our own worse enemy. Back in 95, it took that French student days to crack the 40-bit codes. Now we are talking about minutes... its disheartening. Merde. I really wonder how some of those MS sites survive these days... - Original Message - From: Dave Paris [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, August 11, 2003 06:16 PM Subject: Re: high-grade vs low-grade encryption with MD5 and DES compromised is probably a poor word to use, pointlessly weak is more accurate. If you're going to use SSL and you're dealing with data that needs to be protected longer than 5 minutes, use 128bit SSL. -dsp On Sunday, Aug 10, 2003, at 02:25 US/Eastern, Arthur Chan wrote: Hi all. Verisign currently has a discount on both a high grade (128bits) SSL encrypted and a low grade (40bits) SSL encrypted certificates. The former is priced at US$895 and the latter at US$1395. I noticed some sites also present Verisign certificates with low-grade, 54-bits encryption from their Microsoft/IIS servers. However I cannot find a 54-bits certificate in www.verisign.com/products/site/commerce/index.html Is this 54-bits affair only for Microsoft / IIS ??? Is low-grade encryption with 40 and 54 bits considered compromised ??? Are there any finance/insurance industry standard requiring a 128 bits, high-grade encryption ??? __ Apache Interface to OpenSSL (mod_ssl) www.modssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager[EMAIL PROTECTED] __ Apache Interface to OpenSSL (mod_ssl) www.modssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager[EMAIL PROTECTED] __ Apache Interface to OpenSSL (mod_ssl) www.modssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager[EMAIL PROTECTED] __ Apache Interface to OpenSSL (mod_ssl
Re: high-grade vs low-grade encryption with MD5 and DES
compromised is probably a poor word to use, pointlessly weak is more accurate. If you're going to use SSL and you're dealing with data that needs to be protected longer than 5 minutes, use 128bit SSL. -dsp On Sunday, Aug 10, 2003, at 02:25 US/Eastern, Arthur Chan wrote: Hi all. Verisign currently has a discount on both a high grade (128bits) SSL encrypted and a low grade (40bits) SSL encrypted certificates. The former is priced at US$895 and the latter at US$1395. I noticed some sites also present Verisign certificates with low-grade, 54-bits encryption from their Microsoft/IIS servers. However I cannot find a 54-bits certificate in www.verisign.com/products/site/commerce/index.html Is this 54-bits affair only for Microsoft / IIS ??? Is low-grade encryption with 40 and 54 bits considered compromised ??? Are there any finance/insurance industry standard requiring a 128 bits, high-grade encryption ??? __ Apache Interface to OpenSSL (mod_ssl) www.modssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager[EMAIL PROTECTED] __ Apache Interface to OpenSSL (mod_ssl) www.modssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager[EMAIL PROTECTED]
