Quote from: picobit on October 31, 2015, 09:19:19 AM

Thanks! But that is slightly different, I will end up with needing to sign each transaction on multiple computers. That is highly useful, but not for me, I just need a single offline wallet on a raspberry pi. It is only the backup I need to split, with Shamir secret sharing scheme, or something like that.

No, you can sign the transaction with a single wallet that holds all the seeds.
Create a bunch of seeds, then go to "restore wallet", pick "multisig", and enter your seeds there.

Edit:
You could also create a xprv key with Shamir Secret Sharing, and restore your wallet from it. This will not require multisig transactions.
Unfortunately there is no way to do this directly in Electrum.
What you need is a tool that takes a xprv key (or an Electrum seedphrase), and splits it using Shamir Sectet Sharing.
Maybe we could add such a tool to Electrum.