He has worked previously in mostly corporate and private context, so 2048 is just fine. Now he works with people and data NSA wants their hands on and he wants the data to be secure also in the future. It's just reasonable to move to 4096 key sizes.
>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 knowledgeable 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.
Your secrets are not safe against multinational corporations with 1024 bit keys. The likely cost of the capability to break a 1024 bit key is probably (for a private entity) in the low tens of millions. You wouldn't even be safe from the operators of HN with that margin of security.
Now you've got me imagining what kind of data / communications would be deemed valuable enough to someone to make that kind of monetary expenditure worthwhile.
He has worked previously in mostly corporate and private context, so 2048 is just fine. Now he works with people and data NSA wants their hands on and he wants the data to be secure also in the future. It's just reasonable to move to 4096 key sizes.
http://www.pgp.net/pgpnet/pgp-faq/pgp-faq-keys.html#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 knowledgeable 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.
See also: http://www.keylength.com