[Full Changelog](https://github.com/matrix-org/matrix-js-sdk/compare/v5.1.0...v5.1.1-rc.1) * refactor megolm encryption to improve perceived speed [\#1252](https://github.com/matrix-org/matrix-js-sdk/pull/1252) * Remove v1 identity server fallbacks [\#1253](https://github.com/matrix-org/matrix-js-sdk/pull/1253) * Use alt_aliases instead of local ones for room names [\#1251](https://github.com/matrix-org/matrix-js-sdk/pull/1251) * Upload cross-signing key signatures in the background [\#1250](https://github.com/matrix-org/matrix-js-sdk/pull/1250) * Fix secret sharing names to match spec [\#1249](https://github.com/matrix-org/matrix-js-sdk/pull/1249) * Cleanup: remove crypto.verification.start event [\#1248](https://github.com/matrix-org/matrix-js-sdk/pull/1248) * Fix regression in key backup request params [\#1246](https://github.com/matrix-org/matrix-js-sdk/pull/1246) * Use cross-signing trust to mark backups verified [\#1244](https://github.com/matrix-org/matrix-js-sdk/pull/1244) * Check both cross-signing and local trust for key sharing [\#1243](https://github.com/matrix-org/matrix-js-sdk/pull/1243) * Fixed up tests to match new way that crypto stores are created [\#1242](https://github.com/matrix-org/matrix-js-sdk/pull/1242) * Store USK and SSK locally [\#1235](https://github.com/matrix-org/matrix-js-sdk/pull/1235) * Use unpadded base64 for QR code secrets [\#1236](https://github.com/matrix-org/matrix-js-sdk/pull/1236) * Don't require .done event for finishing self-verification [\#1239](https://github.com/matrix-org/matrix-js-sdk/pull/1239) * Don't cancel as 3rd party in verification request [\#1237](https://github.com/matrix-org/matrix-js-sdk/pull/1237) * Verification: log when switching start event [\#1234](https://github.com/matrix-org/matrix-js-sdk/pull/1234) * Perform crypto store operations directly after transaction [\#1233](https://github.com/matrix-org/matrix-js-sdk/pull/1233) * More verification request logging [\#1232](https://github.com/matrix-org/matrix-js-sdk/pull/1232) * Upgrade deps [\#1231](https://github.com/matrix-org/matrix-js-sdk/pull/1231)