*.springer.com1 observationsIssuerYR2 Let's EncryptValidity2026-09-23 to 2026-12-22Observed2026-09-26 09:08:13to2026-09-26 09:08:13SHA-25627d5c26b2047ca2b459030694a9fed4e68157c22b802be2ffb231ee09d327350⧉