| ??? 02/25/08 21:31 Read: times |
#151450 - there is little difference... Responding to: ???'s previous message |
... between encrypted and unencrypted IAP, as far as programming effort is concerned.
The biggest undertaking is IMHO IAP, as it's device dependent and most of the knowledge cannot be transferred between the various derivatives supporting IAP - and they are many, almost all medium-to-high-end FLASH-containing '51s today. Once you get IAP right, it's only a proper block or stream cipher to scramble/descramble the data. <shameless self-advertisement>You can get a couple of low-footprint block ciphers implementations optimised for '51 from the code library or my webpage.</shameless self-advertisement> These are not as heavyweight as AES & co. but IMHO more than sufficient for this task (about the same as DES). AES is not that hard to implement on '51, but it's questionable whether it's worth the hassle. DES is certainly not worth - it's more complex and less modern than AES. So, briefly - take your IAP implementation, grab on XTEA, choose an appropriate scheme for generating keys (per-user or per-application, depending on the application and infrastructure), stitch together a PC-application providing the encryption, and glue it all together. If I managed, anybody could... ;-) JW |
| Topic | Author | Date |
| Secure IAP (In Application Programming) | 01/01/70 00:00 | |
| It is not THAT important | 01/01/70 00:00 | |
| Encryption | 01/01/70 00:00 | |
| not necessarily | 01/01/70 00:00 | |
| 2 minutes? | 01/01/70 00:00 | |
| Encryption worth it? | 01/01/70 00:00 | |
| the philosophical thread continued | 01/01/70 00:00 | |
if you want to make it really painful ... | 01/01/70 00:00 | |
| ansered by e-mail | 01/01/70 00:00 | |
| the balancing act | 01/01/70 00:00 | |
| there is little difference... | 01/01/70 00:00 | |
| bootloader | 01/01/70 00:00 | |
| On a SiLabs F02x or similar | 01/01/70 00:00 | |
| it's the same on other derivatives, too... | 01/01/70 00:00 |