Why certified/authenticated email cannot solve spam

There are a number of schemes for dealing with spam that boil down to'people will get SSL certificates, you only accept email with a validcertificate, and if people still spam the certificate authority willrevoke their certificate'. There is a simple, core problem with theseschemes:

Certificate revocation never works.

Certificate authorities are paid by the people who they issuecertificates to, not by the people accepting those certificates. Thepeople who provide the money do not want their certificates revoked, andso it is not in


Memory

Both the movies "Atonement" and "The Kite Runners" are pretty exclusively about redemption and remorse, dragging me through the stories of bitter memory. As we grow older, like the English Briony Tallis or the Afghan Amir, we leave behind each one of us a tail – a tail that we feel ashamed and would like to redeem badly.

The memory a dog killed by our cars reminds us our reckless driving. The dirty words we used when we were angry with our classmate haunt us for months, if not

Isolating network interfaces on Linux

Consider a not entirely hypothetical situation: you have an officemachine that serves as one end of a GRE tunnel ,and, in addition to its official network interface, has a fluctuatingnumber of secondary interfaces on various internal VLANs for testing,debugging, and so on. The simple approach for such a machine is to justturn on global IP forwarding and cross your fingers that no one willdecide to make the machine their gateway (apart from the GRE link). Butthis is not ideal; if nothing else,


20080201 網摘 – 這個一月真瘋狂

博益

奇拿


自我三題

1.
21歲時,我就在聽這種歌。


睡到失眠
彭羚(《一枝花》)
作詞:林夕 作曲:梁翹柏 編曲:四方果

平靜得不需要有耳朵
緩慢得聽見汗從左轉右走過
甜蜜得不感覺到何謂飢餓
柔順得可以在誰的髮上仰臥

*拿捏著夢中一片浮雲

The sysadmin's life (again)

I made a bugfix to our mail server's configuration today.

Size of the bugfix: 25 characters added to an existing line.

Size of the comment sort of explaining why the bugfix is necessary: sixlines.

(And a complete discussion of the issue would be much longer.)

Of course, this is not unique to system administration; programmingalso has that sort of bugfixes. I think system administration may bemore prone to it, because so few of our tools, especially the ones with complicated logic


Linux's IP forwarding settings summarized

Unlike many Unixes, Linux determines whether or not it does IPforwarding on an interface by interface basis, based on interface thepacket arrived on . While Linux has a global IP forwarding sysctl, net.ipv4.ip_forward , pretty much all this really does is (re)set thevalue for all of the interfaces and make it the default; you can stillchange individual interfaces later.

The fine controls are in /proc/sys/net/ipv4/conf/ , where thingsgo like


自由的幻影


有個朋友的口頭禪是:“好悶呀,我好想死!”朋友很年輕,戀愛有成,工作穩定,收入也相當不錯,但他每日都習慣“想死”幾十次,當然他至今仍然健在,但我從來沒有聽過他正確地說出眞正的渴求,他需要的,不是死,而

因接近死亡而潦草

正因為是一個很願意為作者付出的讀者,那個專欄的結集出版對我來說才是那麼難以承受的事。

前幾天在某處看到那些短文拼在一起,組成一個可以連接地讀下去的檔案界面,那些我已經為之傾倒過的文字,我一面滾動浮標,一

我好depressed

我好depressed,因為今晚要飛。

我好depressed,因為減肥尚未成功。

我好depressed,因為就o黎姨媽到。

我好depressed,因為我想轉工。

我好depressed,因為天水圍凍到仆街。

我好depressed,因為尋晚俾左家用。

我好depressed,因為媽媽搶左我新買既Kate Spade。

我好depressed,因為想買