Authentication Problem Summary

Cryptography Basement:

• Collision-resistant hash functions(MD5,SHA-256 ...)
• Public-key digital signature schemes (RSA,ECC)
• A Signature Aggregation Scheme (Condensed-RSA)
• The Merkle Hash Tree

Condensed RSA:
The Condensed-RSA scheme discussed in this section is
a simple extension of the standard RSA [4] scheme. One
of the well-known features of RSA is its multiplicative homomorphic
property. This feature makes RSA suitable for
combining signatures generated by a single signer into a single
“condensed” signature. Having successfully verified a
condensed signature, a verifier can be assured that each individual
message covered by the condensed signature was,
indeed, properly signed by the purported signer. RSA signatures
can be condensed “incrementally” by any party in
possession of individual message signatures.

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