Thin Client Security

Recently there have been a number of proposals for bitcoin clients which do not store a copy of the entire block chain. I will refer to all such clients as "thin clients". This page is meant to be a place to try to make sense of the security and trust implications of the various schemes.

Thin Client Strategies

Simplified Payment Verification

This scheme is described in section 8 of the original bitcoin whitepaper.

BCCAPI

Clients are vulnerable to a double-spend attack against them by the server. Therefore, they are implicitly trusting it.

Electrum

Clients are vulnerable to a double-spend attack against them by the server. Therefore, they are implicitly trusting it.

Other

• A thread on bitcoin-dev