Amino encode not support some special char(<, >, $).

[loin3]

When Tx memo contain special characters (<, >, $), Amino sign does not working

Step1. Write Tx with memo within special char. ex) "Tx & Send"
Step2. Sign with Secp256k1HdWallet

signature verification failed; please verify account number (1), sequence (7) and chain-id (simd-testing): unauthorized

[loin3]

keplr-wallet already dealt with this problem, but did not contributed to cosmjs.
https://github.com/chainapsis/keplr-wallet/blob/master/packages/common/src/escape/index.ts#L8

[webmaster128]

Very interesting, thank you for bringing this up. This is indeed not yet implemented.

The Keplr reference is great and helpful.

https://go.dev/play/p/p3RNTpm2LED shows the escaping bahaviour in Go.