[Cryptography] Security proof for RSA PKCS #1 v1.5

[Peter Gutmann]

On the Security of the PKCS#1 v1.5 Signature Scheme
Tibor Jager and Saqib A. Kakvi and Alexander May
https://eprint.iacr.org/2018/855

  We present the first security proofs for RSA PKCS#1 v1.5.  We prove full
  existential un-forgeability under adaptive chosen message attacks (UF - CMA)
  in the random oracle model.  This is the same security level that other
  practical signature schemes, such as RSA-PSS or RSA Full-Domain Hash
  provably achieve.

Peter.