ephemelier

README

The Ephemelier Operating System

The Ephemelier operating system is an MPC virtual machine and execution environment. It executes programs in the "MPC space" i.e. the Ephemelier nodes can't access the memory or the computation of the programs.

Example

The following commands are run in the cmd/ephemelier directory.

First, start the evaluator node:

$ ./ephemelier -e -ktrace
Ephemelier Evaluator Node
Listening for MPC connections at :9000

Next, start the garbler node:

./ephemelier -ktrace -console
Ephemelier Garbler Node
Console running at :2323

Finally, connect to the console port via telnet:

$ telnet localhost 2323
Trying ::1...
Connected to localhost.
Escape character is '^]'.
Ephemelier v0.0 - Copyright (c) 2025 Markku Rossi
esh $ Ephemelier
Hello, Ephemelier!
esh $ exit
Connection closed by foreign host.

HTTPS Server

TLS cipher suites

The cipher suite is hardcoded to TLS_CHACHA20_POLY1305_SHA256. To change it to TLS_AES_128_GCM_SHA256, edit:

• mpc/pkg/crypto/tls/cipher.mpcl to use gcm.{Seal,Open}AES128 instead of chacha20poly1305.{Seal,Open}
• configure cipher suite in crypto/tls/tls.go
• configure cipher key size in pkg/ephemelier/tlsmem/tlsmem.mpcl

Creating HTTPS private key and certificate

$ cd cmd/apps/ephemelier
$ ../tss/tss keygen
...
E: compressed: 0461108f1e6572a06f75bae4b4b603759e0f31d0cf48fa7fe4583765a185a569bc96209ab639b21dbc6f731e115626e907ae3e6556acb46b486de5c55173d7b862
 ../../../nap/cmd/unspammer/unspammer -ca ../../../nap/cmd/unspammer/nap -create-ee localhost -pubkey 0461108f1e6572a06f75bae4b4b603759e0f31d0cf48fa7fe4583765a185a569bc96209ab639b21dbc6f731e115626e907ae3e6556acb46b486de5c55173d7b862
$ ../vault/vault -o data/vault0/httpd -t P-256 import peer-G.share ee-cert.pem
$ ../vault/vault -o data/vault1/httpd -t P-256 import peer-E.share

TODO

• Multi-Party Threshold Signature Scheme
• Circuit stats in streaming mode (INFO)
• Optimize input setting (direct vs. via strings)
• Review mpc/ot
• Review mpc/vole
• Review SPDZ Implementation
• Implement Ephemelier State Machine Compiler
• MPC compiler: -timestamp-dynamic option for the -circ mode to create timestamp file only if main's arguments have unspecified types
• WASM as an intermediate language?
• RISC-V as an intermediate language?

Benchmarks

HTTPD	Time	Relative
1st roundtrip	14.203s	1.000
Optimized main	12.514s	0.881
Semihonest mem	7.183s	0.506
ChaCha20Poly1305	6.393s	0.450
ChaCha20 native block	5.152s	0.363
Optimized input	4.956s	0.349
New HTTPD	5.785s	0.407
IKNP OT	4.918s	0.346
Threshold signatures	5.296s	0.373
HTTPD memory	5.693s	0.401

Fibo	Time	Relative
Baseline	2.736s	1.000
Semihonest mem	0.814s	0.298
Optimized input	0.796s	0.291
IKNP OT	0.352s	0.129