Use of SHA-1 prevents use of third party add-on
Dallas Semiconductors (www.dalsemi.com) has developed a very small integrated circuit (the DS2703) for use in rechargable battery packs that communicates with a cell phone (or digital camera, notebooks, PDAs, etc.) and verifies the authenticity of the battery pack. It uses SHA-1 and a 64-bit secret key in the proces of verification.
This way the use of third party battery packs will be a thing of the past. Price and size has prevented large scale use of this technique up until now, but at US$ 0,77 per chip I guess the main cell phone manufacturers will jump to the occasion and incorporate this (or similar) chip in their battery packs to prevent users from using unsafe packs in stead.
My guess is that we will see much more of this kind of device- or add-on authentication in the near future, especially in situations where revenue depends on sales of authentic add-ons (like the mentioned battery packs, but how about ink and toner cartridges and the like) and situations where the safety or regulatory approval of a system could be comprimised by using non-authentic add ons.
Who would have guessed? Battery packs doing complicated math…
Dallas has a nice white paper about this application of SHA-1 on their Maxim site: www.maxim-ic.com/appnotes.cfm/appnote_number/1201
