Silk Road forums
Discussion => Security => Topic started by: Chip Douglas on August 12, 2013, 07:22 am
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I'm told that's a low number and that there should be an option when I generate my key to get a 4096 RSA.
I tried to do that, and I don't see an option. Should I trash my key and start over, or can someone suggest a better encryption client? This old dog is trying hos darndest to learn new tricks, though this trick could make a differnce between freedom and incarceration, so I'm finally taking it seriously.
All 'helpful' comments welcomed.
8) Chip 8)
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I just checked and the highest you can make it on GNU Privacy Assistant (GPA) is 3072 bits. I assume more bits = more protection, although I'm still unaware of any way someone except the recipient could read your message. Besides someone having access to your computer and having your keys and shit.
EDIT: Here's a link (CLEARNET) with some info: http://www.pgp.net/pgpnet/pgp-faq/pgp-faq-keys.html#key-size
"Q: Which key size should I use?
A: PGP gives you choices for RSA and DSA key size ranging from 512 to 2048 or even 4096 bits. The larger the key, the more secure the RSA/DSA portion of the encryption is. The only place where the key size makes a large change in the running time of the program is during key generation. A 1024 bit key can take 8 times longer to generate than a 384 bit key. Fortunately, this is a one time process that doesn't need to be repeated unless you wish to generate another key pair.
During encryption, only the RSA portion of the encryption process is affected by key size. The RSA portion is only used for encrypting the session key used by the the symmetrical algorithm (IDEA, 3DES, CAST etcetera). The main body of the message is totally unaffected by the choice of RSA key size.
Dr Lenstra and Dr Verheul offer their recommendations for keylengths. In their calculation, a 2048 bit key should keep your secrets safe at least until 2020 against very highly funded and knowledgable adversaries (i.e. you have the NSA working against you). Against lesser adversaries such as mere multinationals your secret should be safe against bruteforce cryptoanalysis much longer, even with 1024 bit keys.
So unless you have a very good reason for doing otherwise, select the 1024 or 2048 bit key size. Using currently available algorithms for factoring and available computing power, the 384 and 512 bit keys are known to be within reach of adversaries and 768 is questionable"
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Thank you very much. I'm finally learning it because thanks to the NSA story, PGP has almost become a religion on here. Personally, and this is from a laymans perspective, but one who worked along side IT pros, installing FIOS equipment during it's rollout approx 10 yrs ago. It seems to me, if someone's watching you from the CO, then they can see what you're typing before you encrypt it. They can also see your PGP key, and they can also see you decrypt a message from someone. They used to monitor customers internet usage with a DVR on 24/7.
I'm playing along, but deep down I feel like those that are watching us are laughing at our futile attempts to hide our information. I may not know the particulars, and certainly can't impress anyone with fancy IT shop talk, but I know what I saw.
I also think the whole NSA spying story was purposely leaked to cover up the more serious crimes committed by Obama + Co using the IRS to go after political opponents, the gun running to Mexico, Benghazi, and basically his working for Al-Queda and the Muslim Brotherhood. This guy makes Nixon look like a boyscout!
Sorry, but I needed that rant. Hopefully the paranoid PGP fascists will realize that the tail is wagging the dog one day.
One can still hope!
Thanks a million
8) Chip 8)
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I just checked and the highest you can make it on GNU Privacy Assistant (GPA) is 3072 bits. I assume more bits = more protection, although I'm still unaware of any way someone except the recipient could read your message. Besides someone having access to your computer and having your keys and shit.
EDIT: Here's a link (CLEARNET) with some info: http://www.pgp.net/pgpnet/pgp-faq/pgp-faq-keys.html#key-size
"Q: Which key size should I use?
A: PGP gives you choices for RSA and DSA key size ranging from 512 to 2048 or even 4096 bits. The larger the key, the more secure the RSA/DSA portion of the encryption is. The only place where the key size makes a large change in the running time of the program is during key generation. A 1024 bit key can take 8 times longer to generate than a 384 bit key. Fortunately, this is a one time process that doesn't need to be repeated unless you wish to generate another key pair.
During encryption, only the RSA portion of the encryption process is affected by key size. The RSA portion is only used for encrypting the session key used by the the symmetrical algorithm (IDEA, 3DES, CAST etcetera). The main body of the message is totally unaffected by the choice of RSA key size.
Dr Lenstra and Dr Verheul offer their recommendations for keylengths. In their calculation, a 2048 bit key should keep your secrets safe at least until 2020 against very highly funded and knowledgable adversaries (i.e. you have the NSA working against you). Against lesser adversaries such as mere multinationals your secret should be safe against bruteforce cryptoanalysis much longer, even with 1024 bit keys.
So unless you have a very good reason for doing otherwise, select the 1024 or 2048 bit key size. Using currently available algorithms for factoring and available computing power, the 384 and 512 bit keys are known to be within reach of adversaries and 768 is questionable"
Here is a little section from Louis Cyphere's Security Guides for you to read -
- DES used to be standard many years ago, but it has only 56 bits, so it’s not at all secure these days. Triple DES is a straightforward way of increasing the key length by applying DES three times (with three independent keys). This gives a key length of 3×56=168, but because of a known possible attack, the security is, in practice, only 112 bits. If you want more security than that, you’ll need to use a different algorithm. Triple DES has no known security breaches, but it is computationally slow. It’s still the default algorithm in the OpenPGP standard, but not in GPG any more.
- CAST5 (a.k.a. CAST-128) is a symmetric algorithm with a key size between 40 and 128 bits; if you’re going to use it, go for 128 bits. In most Linux installations, it’s the current GPG default. At present, there is no known way of breaking it short of brute force, so its security is also 128 bits.
- Blowfish key length is between 32 bits and 448 bits, so you have a reasonable choice (32 bits is basically pretty useless). Unfortunately, it does need a fair bit of memory. Blowfish is similar in structure to CAST5. Twofish is a similar algorithm, with a longer block size and key length of up to 256 bits. Neither has been cryptographically broken, but security specialist Bruce Schneier recommends the use of Twofish over Blowfish.
- AES stands for Advanced Encryption Standard and is now the NIST technique of choice to replace DES (formerly the most often used standard). AES uses a 128-bit key, AES192 uses a 198-bit key, and AES256 uses a 256-bit key. Each of these also uses a slightly more complicated algorithm than its smaller relatives. Which of these to choose is a little complicated, and cryptographers disagree. There are attacks on AES-256 and AES-192 that don’t exist on AES-128, but they’re still considered “secure” because of the computational cost of those attacks (i.e., it’s not in practice feasible to break them).
- AES-128 is a bit faster than AES-256, so it might be a more practical option; AES-256 probably isn’t any weaker than AES-128. Keys of 128 bits are likely to be secure for somewhere between 10 and 50 years, depending on whom you ask. AES is now the official US government standard (128-bit for secret classified information, 192- or 256-bit for top secret).
- Other ciphers are also available (e.g., the CAMELLIA ciphers used as the Japanese encryption standard).
Taking public key and cipher together, for a decent balance between security and speed, AES (128 or 256) or CAST5 with RSA 2048 is your best bet (AES+RSA is recommended by NASA). Certainly, if you want long-term security, you shouldn’t go with an asymmetric key length of less than 2048 bits or a symmetric key length of less than 128 bits. For more security over the much longer term, but at a slight performance cost, choose a longer RSA key length (e.g., 4096 bits). [4]
1024 bit keys are not safe to use anymore. This was the max. key size used by PGP Portable which was able to be cracked. It's not safe to use.
At a bare minimum, you will want a 2048 bit key. IMO, you should go with a key size of 4096 bits.
Try this software instead of GPA - http://gpg4usb.cpunk.de/download.html - works across Windows, Mac and Linuix O/S.
Here's a link to astor's tutorial on using gpg4usb - http://nfm5tbykjg6oijbm.onion/gpg4usb/
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i dunno, use gpg in command line.
compile the source your self. you can edit 2 lines in the program and allow larger keys. I can make 8192 bit keys and larger.
you could also start to adopt 521 bit ecc keys..
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I'm told that's a low number and that there should be an option when I generate my key to get a 4096 RSA.
The larger the key size, the harder it is for an attacker to guess the key through brute force generation of random keys. 2048 bits is considered secure for a few more decades. Key sizes can be too big for current technology, too. Many PGP programs don't support key sizes above 4096 bits, and I don't know of any that support key sizes above 8192 bits without being modified. Right now, 4096 bits is optimal, but 2048 bits is also acceptable.
Here is a little section from Louis Cyphere's Security Guides for you to read -
- DES used to be standard many years ago, but it has only 56 bits, so it’s not at all secure these days. Triple DES is a straightforward way of increasing the key length by applying DES three times (with three independent keys). This gives a key length of 3×56=168, but because of a known possible attack, the security is, in practice, only 112 bits. If you want more security than that, you’ll need to use a different algorithm. Triple DES has no known security breaches, but it is computationally slow. It’s still the default algorithm in the OpenPGP standard, but not in GPG any more.
- CAST5 (a.k.a. CAST-128) is a symmetric algorithm with a key size between 40 and 128 bits; if you’re going to use it, go for 128 bits. In most Linux installations, it’s the current GPG default. At present, there is no known way of breaking it short of brute force, so its security is also 128 bits.
- Blowfish key length is between 32 bits and 448 bits, so you have a reasonable choice (32 bits is basically pretty useless). Unfortunately, it does need a fair bit of memory. Blowfish is similar in structure to CAST5. Twofish is a similar algorithm, with a longer block size and key length of up to 256 bits. Neither has been cryptographically broken, but security specialist Bruce Schneier recommends the use of Twofish over Blowfish.
- AES stands for Advanced Encryption Standard and is now the NIST technique of choice to replace DES (formerly the most often used standard). AES uses a 128-bit key, AES192 uses a 198-bit key, and AES256 uses a 256-bit key. Each of these also uses a slightly more complicated algorithm than its smaller relatives. Which of these to choose is a little complicated, and cryptographers disagree. There are attacks on AES-256 and AES-192 that don’t exist on AES-128, but they’re still considered “secure” because of the computational cost of those attacks (i.e., it’s not in practice feasible to break them).
- AES-128 is a bit faster than AES-256, so it might be a more practical option; AES-256 probably isn’t any weaker than AES-128. Keys of 128 bits are likely to be secure for somewhere between 10 and 50 years, depending on whom you ask. AES is now the official US government standard (128-bit for secret classified information, 192- or 256-bit for top secret).
- Other ciphers are also available (e.g., the CAMELLIA ciphers used as the Japanese encryption standard).
Taking public key and cipher together, for a decent balance between security and speed, AES (128 or 256) or CAST5 with RSA 2048 is your best bet (AES+RSA is recommended by NASA). Certainly, if you want long-term security, you shouldn’t go with an asymmetric key length of less than 2048 bits or a symmetric key length of less than 128 bits. For more security over the much longer term, but at a slight performance cost, choose a longer RSA key length (e.g., 4096 bits). [4]
These are symmetric ciphers, which work differently from asymmetric ciphers such as RSA. You can't directly compare the key strength between symmetric and asymmetric ciphers. As an example, 128 bit AES encryption is stronger than 1024 bit RSA encryption. There are more possible 128 bit AES keys than there are 1024 bit RSA keys, so it would take an attacker more time to brute force guess the key.