{
  "set": "05_key_chain",
  "spec": "core v2 §8.6: a key is laid on top, never replaced; every key of the chain stays valid",
  "binding": {
    "@context": "urn:keysingate:core:v3",
    "type": "AgentBinding",
    "v": 3,
    "emission": "ksg:em:000001",
    "block": {
      "from": 4700000,
      "to": 4700999
    },
    "agent": {
      "kid": "did:key:zAgent#k0",
      "alg": "Ed25519",
      "key": "6S62BU_pvGgqG887dZ9lqzikz72BxNHzNC5Myc3tiws"
    },
    "bound_at": "2026-08-27T10:05:00.000Z",
    "signatures": [
      {
        "kid": "did:key:zAgent#k0",
        "alg": "Ed25519",
        "value": "VHd4d8h3Kn03xjoJNq81uovtOnQSG-5eKBR9otaQ_zUc7ov8Qv1N8Y18VrkV-j1O1N1Vt9hCpUL4N7BaqnqrCA"
      },
      {
        "kid": "did:web:holder.example#h1",
        "alg": "Ed25519",
        "value": "Ql3WIDVI2QbdB0vq2Xtexfk7gFmfme0TPMANFSkGK1JoptVkk0Ze7WTColztCn45MyUHU5J2Wgq6VyvnPN-oBA"
      }
    ]
  },
  "inclusions": [
    {
      "@context": "urn:keysingate:core:v3",
      "type": "KeyInclusion",
      "v": 3,
      "emission": "ksg:em:000001",
      "block": {
        "from": 4700000,
        "to": 4700999
      },
      "predecessor": "12201e6393d3bff9cb715635a5368623ffb8c9b66188c87e772f952b58819918c44c",
      "key": {
        "kid": "did:key:zAgent#k1",
        "alg": "Ed25519",
        "key": "-kg0FH9uaQw2k-_2EzYEZAPNiuKhTzGzxAc1hWkjlWU"
      },
      "offset_ms": 1000,
      "signatures": [
        {
          "kid": "did:key:zAgent#k0",
          "alg": "Ed25519",
          "value": "hwZ9G1brQwY--BEQpD0TSHOjXDYoLKRgufNLfGKUHvh8RuLIhpEEYfTlqK1wrEAK0Q2L1O6IRtPM5Xi8wW2wCA"
        }
      ]
    },
    {
      "@context": "urn:keysingate:core:v3",
      "type": "KeyInclusion",
      "v": 3,
      "emission": "ksg:em:000001",
      "block": {
        "from": 4700000,
        "to": 4700999
      },
      "predecessor": "122085516bdf2608a44c8406548d2fae9466ce7e69f6cb658cc00fee2e5d533c5f01",
      "key": {
        "kid": "did:key:zAgent#k2",
        "alg": "Ed25519",
        "key": "GX9rI-FshTLGq8g4-s1ep4m-DHaykgM0A5v6iz02jWE"
      },
      "offset_ms": 2000,
      "signatures": [
        {
          "kid": "did:key:zAgent#k1",
          "alg": "Ed25519",
          "value": "0ovfw-r0k_AcZAwZfR6SMyXPc8AAPs03MVfG9kHCko0M09Yfss8gwqnVGS0Wttfy9wEdaajCK19QnNZVYBWADw"
        }
      ]
    }
  ],
  "result": {
    "verdict": "accept"
  },
  "key_set": [
    "did:key:zAgent#k0",
    "did:key:zAgent#k1",
    "did:key:zAgent#k2"
  ],
  "cases": [
    {
      "name": "a link that does not follow its predecessor",
      "inclusions": [
        {
          "@context": "urn:keysingate:core:v3",
          "type": "KeyInclusion",
          "v": 3,
          "emission": "ksg:em:000001",
          "block": {
            "from": 4700000,
            "to": 4700999
          },
          "predecessor": "12201e6393d3bff9cb715635a5368623ffb8c9b66188c87e772f952b58819918c44c",
          "key": {
            "kid": "did:key:zAgent#k1",
            "alg": "Ed25519",
            "key": "-kg0FH9uaQw2k-_2EzYEZAPNiuKhTzGzxAc1hWkjlWU"
          },
          "offset_ms": 1000,
          "signatures": [
            {
              "kid": "did:key:zAgent#k0",
              "alg": "Ed25519",
              "value": "hwZ9G1brQwY--BEQpD0TSHOjXDYoLKRgufNLfGKUHvh8RuLIhpEEYfTlqK1wrEAK0Q2L1O6IRtPM5Xi8wW2wCA"
            }
          ]
        },
        {
          "@context": "urn:keysingate:core:v3",
          "type": "KeyInclusion",
          "v": 3,
          "emission": "ksg:em:000001",
          "block": {
            "from": 4700000,
            "to": 4700999
          },
          "predecessor": "12201e6393d3bff9cb715635a5368623ffb8c9b66188c87e772f952b58819918c44c",
          "key": {
            "kid": "did:key:zAgent#k2",
            "alg": "Ed25519",
            "key": "GX9rI-FshTLGq8g4-s1ep4m-DHaykgM0A5v6iz02jWE"
          },
          "offset_ms": 2000,
          "signatures": [
            {
              "kid": "did:key:zAgent#k1",
              "alg": "Ed25519",
              "value": "5n9ioWTq2T9tbA9-8mNgUDOr91f2AK-CPNiYqvL5YLGaO-Y1GlAmikJER1_ucd8GQydiR-RIwaTV-FC3Rg8TAQ"
            }
          ]
        }
      ],
      "result": {
        "verdict": "reject",
        "reason": "key chain: link 1 does not follow the previous one"
      }
    },
    {
      "name": "a link signed by a key other than its predecessor's",
      "inclusions": [
        {
          "@context": "urn:keysingate:core:v3",
          "type": "KeyInclusion",
          "v": 3,
          "emission": "ksg:em:000001",
          "block": {
            "from": 4700000,
            "to": 4700999
          },
          "predecessor": "12201e6393d3bff9cb715635a5368623ffb8c9b66188c87e772f952b58819918c44c",
          "key": {
            "kid": "did:key:zAgent#k1",
            "alg": "Ed25519",
            "key": "-kg0FH9uaQw2k-_2EzYEZAPNiuKhTzGzxAc1hWkjlWU"
          },
          "offset_ms": 1000,
          "signatures": [
            {
              "kid": "did:key:zAgent#k0",
              "alg": "Ed25519",
              "value": "hwZ9G1brQwY--BEQpD0TSHOjXDYoLKRgufNLfGKUHvh8RuLIhpEEYfTlqK1wrEAK0Q2L1O6IRtPM5Xi8wW2wCA"
            }
          ]
        },
        {
          "@context": "urn:keysingate:core:v3",
          "type": "KeyInclusion",
          "v": 3,
          "emission": "ksg:em:000001",
          "block": {
            "from": 4700000,
            "to": 4700999
          },
          "predecessor": "122085516bdf2608a44c8406548d2fae9466ce7e69f6cb658cc00fee2e5d533c5f01",
          "key": {
            "kid": "did:key:zAgent#k2",
            "alg": "Ed25519",
            "key": "GX9rI-FshTLGq8g4-s1ep4m-DHaykgM0A5v6iz02jWE"
          },
          "offset_ms": 2000,
          "signatures": [
            {
              "kid": "did:key:zAgent#k0",
              "alg": "Ed25519",
              "value": "45AcQhb9wB5qECzM7gnuelyQd38TxUdEmsG10v-6S8H3rgONAB999GH4i4hmI2c9mY1izWVSmWePIIceizCEDw"
            }
          ]
        }
      ],
      "result": {
        "verdict": "reject",
        "reason": "key chain: link 1 is not signed by its predecessor"
      }
    },
    {
      "name": "a key already in the set",
      "inclusions": [
        {
          "@context": "urn:keysingate:core:v3",
          "type": "KeyInclusion",
          "v": 3,
          "emission": "ksg:em:000001",
          "block": {
            "from": 4700000,
            "to": 4700999
          },
          "predecessor": "12201e6393d3bff9cb715635a5368623ffb8c9b66188c87e772f952b58819918c44c",
          "key": {
            "kid": "did:key:zAgent#k1",
            "alg": "Ed25519",
            "key": "-kg0FH9uaQw2k-_2EzYEZAPNiuKhTzGzxAc1hWkjlWU"
          },
          "offset_ms": 1000,
          "signatures": [
            {
              "kid": "did:key:zAgent#k0",
              "alg": "Ed25519",
              "value": "hwZ9G1brQwY--BEQpD0TSHOjXDYoLKRgufNLfGKUHvh8RuLIhpEEYfTlqK1wrEAK0Q2L1O6IRtPM5Xi8wW2wCA"
            }
          ]
        },
        {
          "@context": "urn:keysingate:core:v3",
          "type": "KeyInclusion",
          "v": 3,
          "emission": "ksg:em:000001",
          "block": {
            "from": 4700000,
            "to": 4700999
          },
          "predecessor": "122085516bdf2608a44c8406548d2fae9466ce7e69f6cb658cc00fee2e5d533c5f01",
          "key": {
            "kid": "did:key:zAgent#k1",
            "alg": "Ed25519",
            "key": "-kg0FH9uaQw2k-_2EzYEZAPNiuKhTzGzxAc1hWkjlWU"
          },
          "offset_ms": 2000,
          "signatures": [
            {
              "kid": "did:key:zAgent#k1",
              "alg": "Ed25519",
              "value": "a-6hRSS_aeDb0gnXukFE4-C_sNPWxzlqqoLNDfbNHtCdN9wZqrX8_lV3js1LkGasM7KmsmbCWKX_IzyIU1t_DA"
            }
          ]
        }
      ],
      "result": {
        "verdict": "reject",
        "reason": "key chain: the key of link 1 is already in the set"
      }
    }
  ]
}