Verify the Chain

Chain Tree

The tree shows the checked root-to-leaf relationship.

highlighted = computed this step

Read the chain as a tree

The root sits above the leaf because the leaf's signature verifies under the root public key.

root verifies leaf\text{root verifies leaf}
Who trusts whomThe toy root-to-leaf chain is recomputed from the signed digest.Who trusts whom - root verifies leafToy Root CAn=55, e=3Leaf cert binds share 19digest=33, sig=22

The root is the trust anchor

The root node carries n=55 and e=3.

n=55,e=3n=55,\quad e=3
Who trusts whomThe toy root-to-leaf chain is recomputed from the signed digest.Who trusts whom - root verifies leafToy Root CAn=55, e=3Leaf cert binds share 19digest=33, sig=22

The leaf carries the digest and signature

The leaf node shows digest 33 and signature 22.

digest=33,sig=22\text{digest}=33,\quad\text{sig}=22
Who trusts whomThe toy root-to-leaf chain is recomputed from the signed digest.Who trusts whom - root verifies leafToy Root CAn=55, e=3Leaf cert binds share 19digest=33, sig=22

Summary

The tree is not decoration; it is the checked relationship between root and leaf.

checked chain\text{checked chain}
Who trusts whomThe toy root-to-leaf chain is recomputed from the signed digest.Who trusts whom - root verifies leafToy Root CAn=55, e=3Leaf cert binds share 19digest=33, sig=22