Computing veterans remember an old habit of crossing zeros (?) in program listings to avoid confusing them with the letter O, in order to make sure the operator would type the program correctly into the computer. This habit, once necessary, has long been rendered obsolete by the increased availability of editing tools. However, the underlying problem of character resemblance is still there. Today it seems we may have to acquire a similar habit, this time to address an issue much more threatening than mere typos: security. Let us begin with a short recourse to history. On April 7, 2000 an anonymous site published a bogus story intimating that the company PairGain Technologies (NASDAQ:PAIR) was about to be acquired for approximately twice its market value. The site employed the look and feel of the Bloomberg news service, and thus appeared quite authentic to unsuspecting users. To disseminate the "news", a message containing a link to the story was simultaneously posted to the Yahoo message board dedicated to PairGain. The link referred to the phony site by its numerical IP address rather than by name, and thus obscured its true identity. Many readers were convinced by the Bloomberg look and feel, and accepted the story at face value despite its suspicious address. As a result, PairGain stock first jumped 31%, and then fell drastically, incurring severe losses to investors. Attacks like this are relatively easy to detect. A stronger variant of this hoax might have used a domain named bl00mberg. com, (with zeros replacing o's), but even the latter is easily distinguishable from the real thing. However, forthcoming Internet technologies have the potential to make such attacks much more elusive and devastating. A new initiative, promoted by a number of Internet standards bodies including IETF and IANA, allows one to register domain names in national alphabets. This way, for example, Russian news site "gazeta. ru" ("gazeta" means "newspaper" in Russian) might register a more appealing " . ". Far from buzzword compliance, the initiative caters to the genuine needs of non-English-speaking Internet users,, who currently find it difficult to access Web sites otherwise. Several alternative implementations are currently being considered, and we can expect the standardization process to be completed soon. The benefits of this initiative are indisputable. Yet the very idea of such an infrastructure is compromised by the peculiarities of world alphabets. Revisiting our newspaper example, one can observe that Russian letters ",,, " are indistinguishable in writing from their English counterparts. Some of the letters (such as "a") are close etymologically, while others look similar by sheer coincidence. For instance, Russian letter "p" is actually pronounced like "r", but the glyphs of the two letters are identical. As it happens, Russian is not the only such language; other Cyrillic languages may cause similar collisions. With the proposed infrastructure in place, numerous English domain names may be homographed-maliciously misspelled by substitution of non-Latin letters. For example, the Bloomberg attack could have been crafted much more skillfully, by registering a domain name bloomberg. com, where the letters "o" and/or "e" have been faked with Russian substitutes. Without adequate safety mechanisms, this scheme can easily mislead even the most cautious reader. 1 Incidentally, this domain has actually been registered. 2 According to Global Reach's report, the English-speaking population of the Internet was about 62% in 1998, and is forecasted to be as low as 37% by the end of 2002.