Daniel Bleichenbacher
Cryptographer who showed in 1998 that RSA encryption with PKCS #1 v1.5 padding could be broken through error responses.
His 1998 Crypto paper, "Chosen Ciphertext Attacks Against Protocols Based on the RSA Encryption Standard PKCS #1", showed that a server able to tell valid padding from invalid padding can be used to decrypt RSA ciphertexts, including the TLS premaster secret. The attack, now known as the Bleichenbacher attack, has returned in several variants since.
PKCS #1 v2.0 replaced the old padding with OAEP, and TLS 1.3 removed RSA key exchange altogether. Few papers have forced two standards to change, and this one managed it.